A Crack in the Pine Island Glacier Ice Shelf

After more than two weeks of successful flights over Antarctica and its surrounding waters and sea ice, one of the more interesting things NASA's Operation IceBridge team has seen this year is a large crack running across the floating ice shelf of Pine Island Glacier. The team observed the crack on the DC-8's Oct. 14 flight. The flight was designed to get better measurements of the region around the ice shelf's grounding line -- where the shelf meets the landmass under the water. It was also flown to collect data along lines that a ground-based expedition will traverse in the coming months.

That data was collected, as expected. What wasn't expected was the crack.

Pine Island is one of the largest and fastest-moving glaciers in Antarctica. It has captured scientists' attention for years because of the rate at which its ice is thinning. The ice shelf thins, the grounding line retreats and the speed of the glacier increases. As it sits on bedrock below sea level -- West Antarctica is the last place with such so-called "marine glaciers" -- and drains about 10 percent of the West Antarctica ice sheet, scientists are concerned about the impact Pine Island's continued thinning will have on sea level.

Ice shelves naturally calve icebergs to shed ice that flows from the landmass to the sea. However, given Pine Island's prominence as a target of study for glaciologists, the crack is at the very least an interesting observation.

"It's part of a natural cycle, but it's still very interesting and impressive to see up close," said IceBridge project scientist Michael Studinger. "It looks like a significant part of the ice shelf is ready to break off."

The IceBridge team made a preliminary calculation that the area that could calve in the coming months covers about 310 square miles (800 square kilometers), Studinger said.

Peter Rejcek, Editor of The Antarctic Sun, wrote a piece about the crack that notes its location is about nine miles north of where a largely National Science Foundation-funded team, led by Bob Bindschadler of NASA's Goddard Space Flight Center, will drill this December and January. The team will put instruments below the ice shelf to provide data about ice sheet-ocean dynamics.

After arriving at the airport about 7 am, we faced a tough weather situation with clouds across almost all targets. In the end, we decided to head out towards a feature called Recovery Glacier – really an ice stream – that has some unique characteristics that make it worth the long flight there and back and the fuel we need to burn. For background, Robin Bell at Lamont-Doherty Earth Observatory at Columbia University led a paper that got published in Nature (2007) where we documented that this fast flowing ice extends deep inside East Antarctica. It also widens as it goes inland. Only the Lambert Glacier and its adjoining Amery Ice Shelf can really compare to the extent of the Recovery Glacier with the Filchner Ice Shelf. Its scale alone makes understanding the Recovery Glacier important. Because of its isolation from research stations on the continent, it is also rarely measured either from an airborne platform or traverse.

The ice stream of Recovery Glacier distinguishes itself from slower-moving ice by its shredded, rough appearance. Credit: Christopher Shuman/NASA, UMBC/JCET

In the Nature paper, we documented that the Recovery widens its velocity field upstream most likely because of some unique characteristics at the ice-bedrock interface, including some probable lakes – trapped pockets of water or very wet sediment basins. Even some distinct geologic edifices penetrate up into the overlying ice. We showed that these features are located where the ice sheet distinctly changes in character. Here it flattens, accelerates and forms flow features visible at the ice sheet's surface.

Only two ground traverses have reached the Recovery, the US-UK South Pole to Dronning Maud Land effort in 1965-1966 and the Norwegian-US International Polar Year program in 2007-2009. So today’s mission and one earlier this season have taken advantage of the DC-8's long range to get a suite of geophysical sensors along and across it – to define its width, depth (using radar), elevation (using laser altimetry) and the area’s bedrock character including possible subglacial lakes (using gravity and radar). This mission focused on the lower reaches of the Recovery as it bends around the Shackleton Range, joins the smaller Slessor Ice Stream, and pushes off the bedrock to form the majority of the floating Filchner Ice Shelf. If you are trying to place it on the globe, today's research target is almost due south of the Atlantic Ocean.

The US Antarctic Research Program took part in the first traverse across Recovery Glacier in 1965-66. Credit: US Antarctic Research Program

With better luck, we’d see some of the Antarctic Peninsula as we fly to and from our base of operations in Punta Arenas, Chile. We crossed over the Larsen C ice shelf on our way back and it was obvious that the peninsula is once again covered in clouds. The glaciers of the Antarctic Peninsula are much smaller than the Recovery but have been changing dramatically recently. Some glaciers there have lost hundreds of feet in elevation and retreated inland in the past decade due to the collapse of their fringing ice shelves. For example, the Crane Glacier now flows freely into the ocean since the Larsen B ice shelf collapsed in 2002. The significance of ongoing changes to Antarctica’s fringing ice shelves is something that has only recently begun to be fully documented by researchers.

Punta Arenas is currently hosting a US Antarctic Program (USAP) ship, the ARSV Laurence M. Gould, that is doing research in the oceans off of Antarctica, as well as supplying the USAP’s Palmer Station. Punta Arenas is also a logistics hub for a number of other nations who have stations in the Antarctic Peninsula including the British Antarctic Survey (BAS). Two of their Twin Otter support aircraft were at the airport today and are quite distinctive in their black and red paint schemes. Even better though, one of my all-time favorite planes was also there this morning: a modified DC-3 equipped with skis for snow runways. There is just something timeless about its design with its nose up and tail tipped down with big tires under the engines. It reminds you of past explorers in remote Antarctica and reminds you to appreciate all that can be accomplished with it and other great aircraft like the DC-8.

NASA's DC-8 casts its shadow on a peak of the Shackleton Range during a flight to the remote Recovery Glacier region on Oct. 30, 2011. Credit: Michael Studinger/NASA

A Crack in the Pine Island Glacier Ice Shelf
Posted on Oct 26, 2011 09:26:34 AM | Patrick Lynch
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A crack runs across the floating ice shelf of Pine Island Glacier in Antarctica, seen from NASA's DC-8 on Oct. 14, 2011. Credit: Michael Studinger/NASA

Note: IceBridge flew a second mission to the Pine Island region on Wed., Oct. 26. Look for more imagery of the crack coming soon. To see more pictures from the Oct. 14 flight, go to the NASA_ICE flickr page.

After more than two weeks of successful flights over Antarctica and its surrounding waters and sea ice, one of the more interesting things NASA's Operation IceBridge team has seen this year is a large crack running across the floating ice shelf of Pine Island Glacier. The team observed the crack on the DC-8's Oct. 14 flight. The flight was designed to get better measurements of the region around the ice shelf's grounding line -- where the shelf meets the landmass under the water. It was also flown to collect data along lines that a ground-based expedition will traverse in the coming months.

That data was collected, as expected. What wasn't expected was the crack.

Pine Island is one of the largest and fastest-moving glaciers in Antarctica. It has captured scientists' attention for years because of the rate at which its ice is thinning. The ice shelf thins, the grounding line retreats and the speed of the glacier increases. As it sits on bedrock below sea level -- West Antarctica is the last place with such so-called "marine glaciers" -- and drains about 10 percent of the West Antarctica ice sheet, scientists are concerned about the impact Pine Island's continued thinning will have on sea level.

Ice shelves naturally calve icebergs to shed ice that flows from the landmass to the sea. However, given Pine Island's prominence as a target of study for glaciologists, the crack is at the very least an interesting observation.

"It's part of a natural cycle, but it's still very interesting and impressive to see up close," said IceBridge project scientist Michael Studinger. "It looks like a significant part of the ice shelf is ready to break off."

The IceBridge team made a preliminary calculation that the area that could calve in the coming months covers about 310 square miles (800 square kilometers), Studinger said.

The team on the DC-8 observed the crack running across the breadth of the ice shelf. Credit: Michael Studinger/NASA

Peter Rejcek, Editor of The Antarctic Sun, wrote a piece about the crack that notes its location is about nine miles north of where a largely National Science Foundation-funded team, led by Bob Bindschadler of NASA's Goddard Space Flight Center, will drill this December and January. The team will put instruments below the ice shelf to provide data about ice sheet-ocean dynamics.

Rejcek writes:

Bindschadler had previously calculated the propagation of earlier iceberg-releasing cracks at less than 50 meters per day. This crack must have moved much faster across the ice shelf, he said via e-mail.

“The characteristics of the PIG crack that I find surprising are the fact that it is so far across the ice shelf after not having been observed up until the end of last season,” he said.

The location of the crack is near where past rifts have appeared in the ice shelf, according to Bindschadler. He estimated that a new, rather large iceberg will probably form in the coming months, if not weeks.

“I hope that our field team will have enough time to get onto the ice shelf and set up GPS receivers before the calving event,” Bindschadler said. “We’d like to measure if the ice shelf notices the loss.”

Ted Scambos, lead scientist at the Boulder, Colo.-based National Snow and Ice Data Center, agreed that it’s likely that the crack is part of a natural cycle.

“These are cyclical, occurring every few years, very similar in size and even shape,” said Scambos via e-mail. “As a cyclical process, they are not part of the real climate-change/ice-shelf disintegration story.”

In 2002, the Larsen B Ice Shelf on the eastern side of the Antarctic Peninsula disintegrated in spectacular fashion, losing about 3,250 square kilometers of ice in a single season. More recently, the Wilkins Ice Shelf on the western side of the peninsula has started to collapse. Scientists believe both events are linked to climate change, though some researchers have suggested that wave action from distant storms could have helped break up the Wilkins Ice Shelf.

“If something different happened this time; for example, the pace of calvings changed, or this one was farther upstream from the past ones, then it might signal some major change in the Pine Island system,” said Scambos, adding that the area is changing in other ways, but the rate of calving has been steady over the last few decades.


A Second IceBridge Experience: It Just Gets Better
Posted on Oct 22, 2011 03:02:54 PM | Patrick Lynch
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By Nathan Kurtz, NASA's Goddard Space Flight Center and University of Maryland, Baltimore County

Looking back, I'm extremely happy that my second time on the IceBridge mission to the Antarctic was a much more intense experience than my first. Last year bad weather kept us grounded quite often and I was limited to going on three flights over the vast extent of sea ice that surrounds the continent. But this year we hit the ground running, well, flying I should say. There were many more flights, more thrills, more snow, more ice...or was there more snow and ice? In fact, one of the main goals of the IceBridge project is to find out whether the Antarctic is gaining or losing ice. While some regions are gaining ice and others are losing it, the question remains as to whether the sum of the parts is in balance. More importantly, how will the southern polar ice cover drive and respond to changes in the climate? How will these climate impacts affect humanity?

An apron of sea ice floats in front the Brunt Ice Shelf, seen on the first flight of the Antarctica 2011 campaign. Credit: Michael Studinger/NASA

With these questions in mind the DC-8 airplane used for IceBridge launched tirelessly day after day to provide some answers. The plane was loaded with instruments to get a unique look from the air that we cannot get with our eyes and hands. It's amazing for me to think about what great things just a bit of electricity powering the scientific instruments can accomplish (not to mention the massive amounts of coffee apparently fueling the instrument operators). Some electricity fed through an antenna mounted on the aircraft wings produces a radar pulse that can tell us how thick the snow is beneath us. Electricity through a different antenna produces a radar pulse that can tell us how thick the ice is. While even more electricity fed other instruments such as the lasers, gravimeter, and the often-times spectacular photography of all the beautiful areas we pass over.

Outcroppings near Marie Byrd Land. Credit: Michael Studinger/NASA

With all that sensitive equipment loaded on the plane our next step was to fly over interesting areas to measure. We started out with flights in the Weddell Sea to measure the thickness of the sea ice surrounding the Antarctic continent. Antarctic sea ice is a fantastic sight to behold as the strong ocean dynamics in the region create a wide variety in the types of structures that we see. Like a snowflake, no two views of the sea ice are ever the same. In some areas the ice is very consolidated with the ice floes constantly crashing into each other and creating human-sized ridges. In other areas the ice has moved apart, exposing the ocean to the cold polar air and creating intricate geometrical structures as the water freezes and gets stirred together by the wind and ocean.

It is freezing and dynamic processes such as these which determines how much sea ice there is surrounding the Antarctic continent. As a scientist, one of my goals is to use the data collected during these flights to determine how the sea ice is changing and if so, what is causing the changes? How will these changes in such a remote area impact the world at large? It is thought that changes in the sea ice cover will have a large impact on the global temperature by changing the amount of solar radiation absorbed by the Earth. But presently it is not well known how changes in the global temperature will affect the Antarctic sea ice cover. While one may expect warmer temperatures to reduce the amount of ice, it is also possible that complex feedback mechanisms between the ocean and atmosphere could cause the Antarctic sea ice cover to increase with a warming climate. Connecting the observations taken during these IceBridge flights to those from satellites over the past decade will be critical to determining what factors have and will play a part in impacting the ice. While it will take some time to understand what the IceBridge measurements are showing us, there are high hopes for learning a great deal from what has been done.


Path of the IceBridge sea ice flight over the Weddell Sea. Credit: Michael Studinger/NASA

While on my previous flights over sea ice with IceBridge we would often fly near the great ice shelves surrounding the Antarctic continent. To me, the great white ice sheets always looked foreboding, as if they were waiting to swallow up the airplane if we dared venture too far into the interior of the continent to spy on its secrets. This year during my first land ice mission to Pine Island Glacier I half-expected something terrible to happen as soon we crossed the threshold from the ocean to the continent. Thankfully, the plane held a steady pace as if it had absolutely no concern for where it was going. In fact, the plane ended up dutifully flying all over the continent carrying me to some of the most remote and hostile environments on the planet. On the way I saw desolate islands buried in ice, giant crevasses, flew perilously close to lonely mountains with peaks just barely reaching up from the 1+ mile thick sheet of ice covering the land, and so much more. But it didn't seem scary at all, in fact it was quite beautiful! Well, from 1500 ft above the ground everything looked beautiful. At times, the sensors in the plane showed surface temperatures below -50 F and winds blowing at more than 60 mph. Blowing snow was easy to spot with such strong wind. Perhaps not such a cheery and inviting environment to visit, but perched safely on the plane it was easy to appreciate the splendor of the world below. Interestingly, the map display on the plane showed nothing but an ominous black void beyond 80 degrees latitude, the edge of the world apparently. But the mapmakers have it wrong. While the bottom of the world is certainly a vast abyss, it is of white snow and ice rather than a black nothingness.

Given the enormity of the sheet of ice covering Antarctica it's hard to imagine that changes could also be happening to it. Yet, as I've learned many times throughout my experience with IceBridge, it takes sophisticated instruments to learn what is really happening there. With many more flights to go, and countless more hours spent by scientists looking at the instrument data, we will hopefully find out soon enough.

Flying Under A Satellite
Posted on Oct 14, 2011 10:20:01 PM | Patrick Lynch
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By Michael Studinger, IceBridge Project Scientist, NASA Goddard Space Flight Center

Punta Arenas, Chile – Better understanding of changes that occur in the polar ice sheets and sea ice requires observations over many years. With Operation IceBridge we make sure that there are no gaps in these critical measurements. In particular, we "bridge" the gap in laser altimeter measurements from space between ICESat, which ended in 2009, and the follow-up mission ICESat-2, which will launch in 2016. Using data from these two satellite missions and combining them with our aircraft measurements we will be able to build a time series of measurements that spans 17 years. In order to build long time series we often have to combine measurements from different instruments and satellites and it is important to make sure we calibrate and validate these measurements against each other, which will allow us to detect changes in the polar ice sheets and sea ice. The goal of Thursday’s IceBridge mission into the Weddell Sea was to better understand how radar altimeter measurements from ESA’s CryoSat-2 satellite can be combined with laser altimeter measurements from NASA’s IceBridge satellites.

Scarred and chiseled sea ice in the Weddell Sea, where the DC-8 followed in CryoSat-2's tracks on Thursday's IceBridge flight. The DC-8's shadow appears as a dark speck in the lower right. Credit: Michael Studinger/NASA

With IceBridge we are in a unique position to answer these questions because we fly both kinds of instruments on the DC-8 aircraft. In order to compare our measurements we have to fly the DC-8 directly beneath the CryoSat-2 satellite and collect data at the same time in the exact same location. It sounds easier than it is. Many things have to come together to make this happen. First, the weather in the Weddell Sea needs to be suitable for our flight. We need a large, cloud-free area beneath us, which is very rare to find. Second, we need the CryoSat-2 spacecraft on an orbit that allows us to take off from Punta Arenas and fly the DC-8 on the satellite ground track at the same time the spacecraft passes overhead. Third, we need this location to be over a certain type of sea ice that is suitable for comparison of the different measurements. Last, but not least, the weather conditions in Punta Arenas have to be suitable for safe takeoff and landing. Today, we were facing very strong winds that have been close to preventing a flight. While we were flying over the Weddell Sea our colleagues informed us that the winds in Punta Arenas had become so strong that the G-V aircraft had to be moved to Puerto Montt because the wind conditions exceeded the safety specifications for safe parking on the ramp for the G-V. All in all, flying an aircraft directly beneath a satellite in one the most remote parts on Earth is far from trivial. Today, everything went well and the DC-8 flew along the CryoSat-2 ground track in the southern Weddell Sea while the spacecraft passed overhead. The ice conditions were just perfect.

After our rendezvous with CryoSat-2 we reversed course on the ground track to fly back on the same line for 130 kilometers. We did repeat measurements over the exact same segment of our survey line over the course of one hour in order to track the drift of the sea ice. Wind and ocean currents move sea ice floes around. We can estimate how fast and in which direction the sea ice is moving by correlating patterns in our data between the three passes. It is very difficult to make these measurements from space.

After reaching the northern end of our survey line we transit back to Punta Arenas, knowing that we accomplished another landmark sea ice mission for Operation IceBridge.


DC-8 joins G-V for Antarctic IceBridge flights
Posted on Oct 13, 2011 10:37:13 AM | Patrick Lynch
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The Dryden-based DC-8 flight crew handles the plane on its first Antarctica 2011 flight. Credit: Michael Studinger/NASA

By Michael Studinger, IceBridge Project Scientist, NASA Goddard Space Flight Center


Punta Arenas, Chile – Today marks a milestone for IceBridge. For the first time, both NSF’s Gulfstream V (G-V) and NASA’s DC-8 aircraft took off from Punta Arenas for science flights over Antarctica.

The G-V, with NASA’s Land Vegetation and Ice Sensor (LVIS) on board, headed toward Evans Ice Stream, which flows into the southern part of the Ronne Ice Shelf in Antarctica.

The DC-8, with its suite of IceBridge instruments, headed toward the Weddell Sea to measure the thickness of the sea ice and the snow on top of it along two 1,700-km-long transects that cross the entire Weddell Sea from east to west. It’s like flying from Chicago to Miami and back at 1,500 feet above the ground. This mission is an exact repeat of two missions that we have flown in 2009 and 2010. The goal is to measure how much sea ice is being exported through the “gate” connecting the tip of the Antarctic Peninsula with Cape Norvegia and determine the changes that occur over time. The export of sea ice from this area is a major contributor to the total ice volume exported into the Antarctic Circumpolar Current.

The DC-8 takes in a stunning view of the Brunt Ice Shelf on its first Antarctica 2011 flight. Credit: Michael Studinger/NASA

The Weddell Sea encompasses a large area and the chances of getting such a large area cloud-free are small. We rely on several different weather forecast models, satellite imagery and meteorologists at the Punta Arenas airport to get a picture of the weather conditions in the survey area before the flight. It requires many years of experience to interpret the different pieces of information and make a decision in the morning whether we launch a mission into the Weddell Sea or not. There is not a single weather station in the Weddell Sea or nearby to provide observations we could use to confirm the model predictions. Imagine needing to rely on a weather forecast back at home that has no weather data between Chicago and Miami. During the flight we encountered the expected mix of clouds, fog and sunshine. We often were able to fly below the clouds and continue to collect data. All in all a great start to our Antarctic campaign.


Preparing for Punta Arenas
Posted on Oct 05, 2011 08:44:46 PM | Patrick Lynch
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By Michael Studinger, IceBridge Project Scientist, NASA Goddard Space Flight Center


Dryden Flight Research Center, Palmdale, CA – Welcome to another Antarctic campaign with NASA’s Operation IceBridge. Over the next two months the IceBridge teams will be collecting data with two aircraft based in Punta Arenas, located at the southern tip of Chile. We have installed cutting-edge laser altimeters and extremely sensitive radars that will allow us to measure changes in thickness of the sea ice surrounding Antarctica. We will also be monitoring changes in the thickness of ice sheets and glaciers that cover 98% of the Antarctic continent.


NASA's DC-8 flies over Dryden Flight Research Center on a test flight Wednesday before next week's transit to Chile. Credit: Kyle Krabill/NASA

Before we can start collecting data over Antarctica we have to make sure that all installed sensors on NASA's DC-8 work and are calibrated. (The second plane in this fall's campaign, a Gulfstream-V operated by the National Science Foundation and the National Center for Atmospheric Research, has already landed in Punta Arenas and could start science flights as early as Friday.) In order to make extremely precise laser altimeter measurements of the ice surface elevation we use target sites in the Mojave Desert that we have surveyed on the ground to calibrate the instruments. El Mirage, a dry lake bed, not far away from Dryden’s Flight Research Center is a perfect target site to calibrate our laser. We also fly over the ramp at Dryden and over two ICESat ground tracks in the desert to make sure our equipment works. A second test flights takes us out over the Pacific Ocean, some 200 miles away from the coast, where we can switch on our radars without interfering with other systems. We use the radar signal that is bouncing back from the ocean surface to calibrate the radars. We did a couple of maneuvers at high-altitude over the Pacific Ocean to calibrate the antennas of the ice-penetrating radar systems that we will use to survey the sea ice, glaciers, and ice sheets.


The flight track of the DC-8 during a calibration flight over the Mojave Desert in California. Credit: Michael Studinger/NASA

In a few days we will be ready to go south. In previous years we have laid down the foundation for repeat measurements of many glaciers and ice streams in Antarctica. This year we will be re-surveying our previous flight lines in order to determine how much these glaciers have changed compared to previous years. We also plan to survey a few new areas in order to establish baseline measurements for future years and for the upcoming ICESat-2 mission in 2016.

The IceBridge teams have enjoyed working in sunny and warm California for a few weeks, preparing for our trip to Chile. We are looking forward to another successful campaign with exciting new data and spectacular Antarctic scenery. You can follow us on this blog and on Twitter at Twitter.com/nasa_ice.

Measuring Gravity From a Moving Aircraft
Posted on May 18, 2011 09:49:01 AM | Kathryn Hansen
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From: Joël Dubé, Engineer/Geophysicist at Sander Geophysics, OIB P-3 Gravity Team

One of the instruments used in Operation IceBridge (OIB) is an airborne gravimeter operated through a collaboration between Lamont Doherty Earth Observatory of Columbia University and Sander Geophysics. Some people from other instrument teams call it a gravity meter, gravity, gravitometer, gravy meter, gravel meter, gravitron, or blue couch-like instrument. As operators of the gravimeter, we are referred to as graviteers, gravi-geeks or gravi-gods. This tells a lot about how mysterious and unknown this technology appears.

Let me summarize the basics of airborne gravity data acquisition for you.

But first, why is gravity data being acquired as part of OIB?

The earth's gravity field is varying in space according to variations in topography and density distribution under the earth's surface. Essentially, the greatest density contrast is between air (0.001 g/cc), water and ice (1.00 and 0.92 g/cc, respectively) and rocks (2.67 g/cc in average). Therefore, gravity data can be used for modelling the interface between these three elements. The ATM system (laser scanner) can locate the interface between air and whatever is underneath it with great accuracy. The MCoRDS system (ice penetrating radar) is successful at locating the interface underneath the ice. However, no radar system can “see” through water from the air. Hence, gravity data can help determine bathymetry beneath floating ice, either off shore or on shore (sub-glacial lakes). This in turn enables the creation of water circulation models and helps to predict melting of the ice from underneath. Also, airborne gravity data can contribute to increasing the accuracy and resolution of the Earth Gravitational Model (EGM), which is determined only with low resolution in remote locations such as the poles, being built mainly from data acquired with satellites.

Most people don't know that it is possible to acquire accurate gravity data from a moving platform such as an aircraft. Due to the vibrations and accelerations experienced by the aircraft, it is definitively a challenge! There are four key elements that make this possible.

1- You must have very accurate acceleration sensors, called accelerometers.

2- You must keep these accelerometers as stable as possible, and oriented in a fixed direction. This is a job for gyroscopes coupled with a system of motors that keeps the accelerometers fixed in an inertial reference frame, independently of the attitude of the aircraft. This is why the system we use is called AIRGrav, which stands for Airborne Inertially Referenced Gravimeter. Damping is also necessary to reduce transmission of aircraft vibrations to the sensors. The internal temperature of the gravimeter also has to be kept very stable.

This is all good. However, the accelerations we are measuring this way are not only due to the earth's gravity pull, but also (and mostly) due to the aircraft motion. And to correct for that:

3- You need very accurate GPS data, so that you can model the aircraft motion with great precision.

Despite these best efforts, noise remains, mostly from GPS inaccuracies and aircraft vibrations that can't be detected by GPS, so:

4- You have to apply a low pass filter to the data, since the noise amplitude is greatest at high frequency.



The AIRGrav system on-board the P-3 aircraft. Gravimeter (right), rack equipped with computers controlling the gravimeter and GPS receivers (center) and operator (left). Credit: Joël Dubé

Furthermore, a number of corrections have to be applied to the data before they can serve the scientific community. The corrections aim at removing vertical accelerations that have nothing to do with the density distribution at the earth's sub-surface.

The Latitude correction removes the gravity component that is only dependent on latitude. That is the gravity value that would be observed if the earth was treated as a perfect, homogeneous, rotating ellipsoid. This value is also called the normal gravity. Since the earth is flatter at the poles, being at high latitude means you are closer to the earth's mass center, hence the stronger gravity. Also, because of the earth's rotation and the shorter distance to the spinning axis, a point close to the pole moves slower and this will add to gravity as well (less centrifugal force acting against earth's pull).

Anything traveling in the same direction as the earth's rotation (eastward), will experience a stronger centrifugal force thus a weaker gravity, and the other way around in the other direction. Traveling over a curved surface also reduces gravity no matter which direction is flown, similar to feeling lighter on a roller coaster as you come over the top of a hill. This is known as the Eötvös effect and is taken care of by the Eötvös correction. This correction is particularly important for measurements taken from an aircraft moving at 250-300 knots.

The Free Air correction simply accounts for the elevation at which a measurement is taken. The further you are from the earth's center, the weaker the gravity.

To give you an idea of how small the gravity signal that we are interested in is with respect to other vertical accelerations that have to be removed, let's look at the following profiles made from a real data set. All numbers are in mGals (1 m/s2 = 100,000 mGals), except for the terrain and flying height which are in meters.


A visual summary of gravity corrections. Credit: Stefan Elieff

"Raw Gravity" in this diagram means that GPS accelerations (aircraft motions) have been removed from inertial accelerations. Notice the relative scales of the profiles, starting at 200,000 mGals, down to 20,000 mGals when aircraft motions are accounted for, down to 200 mGals after removing most of the high frequency noise, and ending at 50 mGals for Free Air corrected gravity. Free Air gravity is influenced by the air/water/ice/rock interfaces described earlier, and since OIB uses the gravity data to find the rock interface (the unknown), Free Air gravity is the final product. As a side note, for other types of gravity surveys, we usually want to correct for the terrain effect (the air/water/rock interfaces are known in these cases), so that we are left with the gravity influenced only by the variations of density within the rocks. This is called Bouguer gravity and is also shown in the figure.

Notice the inverse correspondence between flying height (last profile, in blue) and the profiles before the free air correction (going higher, further from the earth, decreases gravity), and the correspondence between terrain (last profile, in black) and the free air corrected data.

Now, let's look at some data acquired during the current 2011 mission in western Greenland.


Ice elevation (left), rock elevation (middle) and Free Air gravity data (right). Greenland 2011 flight lines shown in black. Gravity data is preliminary and is not yet available for scientific analysis.

The left panel shows the elevation of the rocks, or of the ice where ice is present. It is as if the water has been drained from the ocean. The middle panel shows only the bedrock elevation, both ice and water being removed. The data is from ETOPO1, a global relief model covering the entire earth. The right panel shows the Free Air gravity acquired in the last few weeks. Most channels, called fjords, are well mapped by the gravity data. It is interesting to see that the gravity data infers the presence of a sub-glacial channel (shown by the red arrow) where no channel is mapped (yet?) on the bedrock map. The most likely reason for this is that this particular region has not been covered by previous ice radar surveys (there are huge portions of the Greenland ice sheet that remain unexplored). Note that the MCoRDS ice radar data acquired as part of the current campaign will improve the resolution in this area and will enable for a better comparison of both data sets in the future.

Asteroid 2005 YU55 Update

601422main_2005_YU55_approach-428NASA scientists are tracking asteroid 2005 YU55 from the agency's Deep Space Network at Goldstone, California. for at least four hours each day from 6th thro 10th November.

Radar observations from the Arecibo Planetary Radar Facility in Puerto Rico will begin on Nov. 8. The space rock will make its closest approach to Earth on Nov. 8 at 3:28 p.m.

The trajectory of asteroid 2005 YU55 is well understood. At the point of closest approach, it will be no closer than 201,700 miles (324,600 kilometers) or 0.85 the distance from the moon to Earth.

YB26SEAG - 26th SEA GAMES 2011

YBDXC_YB26SEAG_Rev_4YB26SEAG is the Special Callsign for the 26th SEA GAMES 2011, Indonesia.

The Special Event Station is on the air November 11-17, 2011, all bands and all modes courtesy of YB Land DX Club operators.

QSL Manager : YB2DX / HANS.

QSL Direct : PO BOX 123 – PW – 58100 – Indonesia.

/MM from Spitzbergen (JW)...

image0021Lars Midtbø, LA2RRA is the cook on the “M / S Nordstjernen,” a ship for transport, built in 1956 and modernized in 1980, adapted to accommodate seafaring passengers traveling the old route to the Archipelago of Spitsbergen (JW).

image001Lars, when off duty works with antenna system and IC-7000 HF rig, while matching the low bands and working digital modes. You can also meet him on 20 meter SSB.

QSLs must be submitted via the bureau.

M / S Nordstjernen, built in the Hamburg, Germany shipyards in 1956, 80 meters long, 13 meters high, keel depth 5 meters .

8Q7CC - Furanafushi Island, IOTA AS-013

upcoming-8q7ccListen out for Cesare I0WDX in the next few days.

He will be active from Furanafushi Island, North Male Atoll, Maldives as 8Q7CC between November 2 – 11, 2011.

QSL is via his home call I0WDX.

Qsl cards to Bureau (or Direct).......

K800_SNV35141Qsl cards processed:

10KG (5 x 2Kg) to the
RSGB Bureau, 2 Kg to JARL;

GB1HI - 284
GB1TAN - 255

M0BZH - 20
PX2C - 62
PYMTV - 75
PW2D - 82
G3SZU - 37,
- 349,
- 179,
- 234,
- 10, MR0IAA - 8,GW8ASA - 3
, RA3CQ - 77, M0AID - 20, G4RCG -10, GR4RCG -70, G1WRS - 122......and a further 120 letters Direct from OQRS and Post Mail.

CQWW SSB looms, V55A make their debut....

v55a_logo_k2CQWW SSB is upon us this weekend and with the increased band activity now the higher bands are open, it promises to be an amazing weekend with lots of new DX.

One of the new Teams out this year are V55A in Namibia. It is their first outing this weekend and we all hope that all goes well for them. They will also have a logbook on-line courtesy of our favourite Clublog.

Also active with be Thomas and Fabio as PW2D and also Andre PY2MTV may make an appreance from home. Listen out for the guys and if you hear them please give them your support. GL guys!

(click the logo to the left for the V55A Log Search)

(Qsl for all above via M0OXO)

GB2HI Hilbre Island EU-120 ''The second coming''

By Kevin M0TNX (GB2HI);

A massive “thanks!” to all the stations we worked this weekend, we decided to pull the plug an hour earlier than expected, we wanted to play radio with our own calls for a bit, and get some reports without the help of the GB2HI call. Here’s the story of GB2HI, October 2011.

As soon as we had finished operating in May, I knew I wanted to get back to Hilbre, not just because of the radio, but because of the sheer beauty of the place, it’s location both radio wise and ecologically. GB2HI was a green operation mart1this time, with the whole operation being run from a wind turbine on the Island. I had started preparing for Hilbre a couple of months ago, I knew from speaking with previous activators from 10 years ago that the Island had never had 160M activation, so being both a 160 and CW nut, I wanted to have a go! Preparations had gone really well, Martin and I had practised putting the 40 foot vertical section up, we had cut the antenna and tried it, all was good. The sunspots were going ballistic and we knew that we were going to have some success. Hilbre this time was determined to make us work for the contacts! Before I go any further, I would like to pass on a huge message of thanks to a few people who made a huge difference, without the help of these people, GB2HI was going to be a non-starter. Lee, G0DBE and his eldest lad, young Lee saved the day once again, more about this later, Ronnie G4DIY, for the loan of the radials and help and advice that is second to none, and last but not least, Keith, G3SZU, cucumber cool, knowledgable and always there when chips are down. Radio wise or not.

I had everything waiting at home, ready for Mart to pick me up when I received a call from Jo Hanick, the senior warden at Wirral Country Park explaining that there was no power available on Hilbre, could we use a generator.. This through me into a bit of an “ARRRRRGGGHHHH!!!” moment, as a) I had no generator, and B) the cost of the fuel along with other bits bought for Hilbre would push me over the edge financially.. For 10 minutes I had seriously thought of pulling the plug on the operation. First person I rang was Lee, G0DBE who kindly offered the loan of his 5KvA generator, and fuel can. I was sort of there, but how would we fit the genny, fuel cans and other bits in the car? Lee’s generosity came into play again when he offered to take the genny for us and pick it up. We got underway on time and arrived at the pick up point to find that Jo had managed to get an Electrician on to Hilbre to sort out the power problem, which took the pressure off, Green Hilbre was still go!
The Lee’s jumped in the Land Rover with us, as we were driven over with Matt, the Warden on duty to Hilbre. Matt is fantastic with his wildlife knowledge, and pointed out the various waders and wildfowl that we couldn’t pick up on. The Lee’s helped us get the mast started, and then had to leave as the tide was turning and they had to leave with Matt.
As the tide came in, it brought a weather front with it, blowing a hoolie, we struggled with the mast, Mart has got a picture on his phone of the mast bent at almost 90 degrees, I was struggling to hold the thing up. radialsWe worked under real pressure and managed after about an hour and a half to get the thing up straight! Changing winds however meant several re jigs of the 40 foot monster!

click here to

Read more: GB2HI Hilbre Island EU-120 ''The second coming''

Comet Storm in a Nearby Star System


NASA's Spitzer Space Telescope has detected signs of icy bodies raining down in an alien solar system. The downpour resembles our own solar system several billion years ago during a period known as the "Late Heavy Bombardment," which may have brought water and other life-forming ingredients to Earth.

During the Late Heavy Bombardment, comets and other frosty objects from the outer solar system pummeled the inner planets. The barrage scarred our Moon and produced large amounts of dust.

Scientists have spotted a band of dust around Eta Corvi that strongly matches the contents of an obliterated giant comet, probably destroyed by a collision with a planet or some other large body. The dust is located close enough to Eta Corvi that Earth-like worlds could exist in the collision zone, suggesting that planets like our own might be involved. The Eta Corvi system is approximately one billion years old, which researchers think is about the right age for such a hailstorm.

A second, more massive ring of colder dust located at the far edge of the Eta Corvi system seems like the proper environment for a reservoir of cometary bodies. This bright ring, discovered in 2005, matches the size of a similar region in our own solar system, known as the Kuiper Belt, where icy and rocky leftovers from planet formation linger. The comets of Eta Corvi and the Almahata Sitta meteorite may have each originated in the Kuiper Belts of their respective star systems.

About 4 billion years ago, not long after our solar system formed, scientists think the Kuiper Belt was disturbed by a migration of Jupiter and Saturn. This jarring shift in the solar system's gravitational balance scattered the icy bodies in the Kuiper Belt, flinging the vast majority into interstellar space and producing cold dust in the belt. Some Kuiper Belt objects, however, were set on inward paths that crossed the orbits of Earth and other rocky planets.

Thailand Floods - HF Operators requested......

article-2047832-0E50777300000578-598_634x388QST, to all Radio Amateurs
15 October 2011

World-wide HF operators are kindly requested to QSY away from 7.060-7.063 at all times due to use by Thailand hams during the massive flood emergency affecting millions of people in North and Central Thailand.

Today, the emergency is on-going with huge areas flooded of from a half to two meters of water, some areas are deeper and a few spotty areas are mostly dry in the region.

News estimates say that the flooding will continue for four to six more days, at its height, and subsidence will be over a month. Clean-up and rebuilding may extend more than a year. The majority of flood radio traffic is being carried on the two meter band by scores of ham volunteers, some of which have had their own homes inundated. It is impossible to estimate how many ham radio operators'
shacks are now affected, but the significant flooding covers huge swaths of the region as seen on http://www.neighborhoodlink.com/Rural_Training_Center-Thailand/pages.

The Thai National Club Station, HS0AC, home of the Radio Amateur Society of Thailand, is threatened tomorrow and is under watch. Timely updates can be seen at http://www.qsl.net/rast in English.

Reported by HS0ZCW, Charly

More Qsl Cards out this week......

K800_IMGQsl cards processed and ready for Bureau:

GB1HI - 321
GB1TAN - 290

M0BZH - 8
PX2C - 32
PYMTV - 35
PW2D - 52
G3SZU - 27
M0OXO - 249
GB0WFF - 177

Rockall 2012 - Postponed....

rockallFrom Col MM0NDX;

Much has happened since the first press release was issued on August 27th. A few days later, we got word that the 2009 MM0RAI/p Rockall team were again going to attempt an activation of EU-189 at the end of September. To cut a long story short, IOTA chasers will be aware that the Belgian team did eventually activate the island, with the aide of a converted navy rescue vessel and large inflatables – we congratulate MM0RAI/p on their achievenment as we all know how heavy the seas can be out there in Autumn.

With careful consideration and much deliberation, we have decided to postpone our intended activation of the islet for at least one year. This decision was not taken easily considering our planning and organisational aspects were going extremely well. Suffice to say, we believe an activation so soon after the Belgian effort now makes Rockall a less attractive target – that is the crux of our decision.

It is not lost on us that the majority of the world, outwith a proportion of Europe, still require EU-189 for their IOTA scores. With that in mind, this planned activity will not be cancelled, only postponed.

All donations will be refunded. We thank sincerely those kind operators and groups who pledged financial support.

What we can say is that another excellent location/target is now being organised. This involves a rare DXCC and IOTA. However, unlike MS0INT 2012 plans, we prefer to keep silent on this, and only release news and website one week before departure, sometime in mid-2012.

icqpodcast - easy listening to Ham Radio topics...

A great way of listening to current Ham Radio news. It includes local and national topics in a formal 'chat' atmosphere and also provides a propagation report.

Its great to improve your knowledge of Ham Radio and gives you the info in basic terms and well explained topics. Give it a try whether in your Shack or on your Ipod/Mobile Fone.

Click the image for a link to the icqpodcast website and then select the 'Latest Podcast' on the left side.

T32C – Christmas Island DXpedition by FSDXA - Update....

T32C_logoHere is the latest news from the T32C eam via their Publicity Manager Don Field;

We have now been operating for four days and have passed the 50,000 QSO milestone. There is still almost 3 weeks to go, so those who are still needing us on various bands and modes have many opportunities still to come. This bulletin is by way of a summary of what has been done and what is planned.

Bear in mind that this has turned out to be something of an unplanned Field Day style operation, and we now have no expectations of our container of equipment arriving while we are here on Christmas Island. Instead, the team hand carried just over one metric tonne of equipment (poles, cables, radio gear, computers, etc) to the island. We are extremely grateful to all those who loaned equipment at short notice to help enable the expedition to take place and be successful. Inevitably we have had teething problems, as we have a variety of amplifiers, Microham routers, etc. where we would, ideally, like to have standard equipment and interfaces. Fortunately the transceivers are consistent as Yaesu came to our rescue with the loan of ten FT-450D radios at very short notice.

Antenna-wise, we have two-element vertical dipole arrays by the sea for 20 through 10, quarter-wave verticals with elevated radials for 30 and 40, a quarter wave vertical with ground radials for 80 and a 15m high T antenna with ground radials for 160. We also have two Beverage receive antennas for 160 and now have additional vertical dipoles for 10, 15 and 20 to allow us to retask the low band stations as second stations on those bands when LF is closed. We are continually refining our antenna systems within the limits of the wire, poles and coax that we have here, though the second tranche of operators who arrive in a week’s time will bring more.

click here to read more....

Read more: T32C – Christmas Island DXpedition by FSDXA - Update....

DX Code of Conduct Update - October 2011

19We have made encouraging progress on almost every front. Over 20,700 hams have visited our site and there is strong representation from hams in countries all around the world. One of our main objectives was to have this be a true international movement.

Take a look at the Flag Counter on our main page and click on it to see more statistics. You may be surprised to see how much support there has been from some countries where the number of supporters is well out of proportion to their population. This is due mostly to small number of hams in those countries who have dedicated themselves to spreading the word about the merits of improving behavior among their compatriots. You can do the same within your country too.

Another feature that shows this also is the rotating globe from Revolver Maps. This shows previous log-ins but will also highlight your QTH when you are at the page. Click on the globe for more detail. The support of DXpeditions has been very encouraging.

Of course, those operators are the major beneficiaries of ethical operating behavior. I have been listening to T32C and 3D2R and the pileups seem quite well-controlled compared with stories I heard about ST0R. That said, I would like someday to understand why, when the DX station asks, "M0?" someone whose call is K4XXX continues to call. There is no way the DX can hear him if he is listening to someone else!

Take a look at www.T32C.com where we are featured on the main page and on http://www.t32c.com/How_to_Work_T32C That kind of prominent notice does a great job in telling DXers that the DXpedition thinks the Code is important and that DXers need to adhere to the Code to better their chances for a contact. Almost every DXpedition is showing their support with a logo and a link. A major thrust for 2011 that you can help with is to get the support of your country's national society. The new page http://dx-code.org/national.html shows societies like RSGB and DARC that are pushing the project in their countries. There are others that are listed, although a few have supported us in the past but I cannot now find a link.

Please take a minute to think about how you can get your country's society to support the project, put the logo up at their website, tell their members about it, perhaps through an article in your society's magazine or newsletter. You can also help by putting the logo on your webpage and on your QSL card the next time you print some. We'd like our logo to be EVERYWHERE so that it will be impossible to miss and so every ham will learn about it.

On behalf of our Committee, I would like to thank you for the hundreds of e-mails I have received expressing the support of the Code project. You can feel good about the worldwide enthusiasm for a project with such high ethical goals. Keep spreading the word.

73, Randy W6SJ

3D2R in the log for M0OXO DXCC 300!!

Rotuma_from_space23D2R operators very loud on 20M CW this morning. I was pleased to make the 'trip' there for DXCC 300!

is a Fijian dependency consisting of Rotuma Island and nearby islets. The island group is home to a small but unique indigenous ethnic group which constitutes a recognizable minority within the population of Fiji, known as "Rotumans". Its population at the 2007 census was 2,002, although many Rotumans live on mainland Fijian islands, totaling 10,000.

These volcanic islands are located at 12°30′42″S 177°51′9″E, 646 kilometres (Suva to Ahau) north of Fiji. Rotuma Island itself is 13 kilometres long and 4 kilometres wide, with a land area of approximately 43 square kilometres. The island is bisected into a larger eastern part, and a western peninsula, by a low narrow isthmus only 230 meters wide, the location of Motusa village (Itu'ti'u district). North of the isthmus is Maka Bay, and in the south Hopmafau Bay. The bays are full of coral reefs, through which there are boat passages.

The Strange Attraction of Gale Crater

Mars_CuriosityCuriosity is about to go to Mars. 

The car-sized rover, also known as the Mars Science Lab, is scheduled for launch in late November or early December 2011 from the Kennedy Space Center.  After an eight-month voyage to Mars, Curiosity will land at the foot of a 3 mile high mountain in a crater named "Gale."

It sounds a little odd—a mountain in the middle of an impact crater. Wouldn't the impact have smashed it flat? Some scientists believe the 96 mile wide crater filled in with sediments over time and relentless Martian winds carved a mountain in the center, where it now stands nearly three times higher than the Grand Canyon is deep.

Because of its history, this strangely sculpted mountain is the ideal place for Curiosity to conduct its mission of exploration into the Red Planet's past.
Today the Red Planet is a radiation-drenched, bitterly cold, bleak world. Enormous dust storms explode across the barren landscape and darken Martian skies for months at a time. But data from the Mars Reconnaissance Orbiter suggest that Mars once hosted vast lakes and flowing rivers. As seasoned travelers know, however, the journey is just as important as the destination. Curiosity can travel up to 150 meters per Mars day, but will stop often to gather and analyze samples. A high-resolution camera on the rover's mast will take pictures and movies of the scenery, taking Earthlings on an extraterrestrial sightseeing tour.

The Secret Lives of Solar Flares

Secret_FlareNASA-supported researchers say that solar flares have been keeping a secret. The new finding, reported in the Astrophysical Journal, suggests that explosions on the sun could affect Earth even more than previously thought.

152 years ago, a man (in England) named Richard Carrington discovered solar flares. It happened at 11:18 AM on the cloudless morning of Thursday, September 1st, 1859. Just as usual on every sunny day, the 33-year-old solar astronomer was busy in his private observatory, projecting an image of the sun onto a screen and sketching what he saw. On that particular morning, he traced the outlines of an enormous group of sunspots. Suddenly, before his eyes, two brilliant beads of white light appeared over the sunspots; they were so bright he could barely stand to look at the screen. It would not be the last. Since then, astronomers have recorded thousands of strong flares using instruments ranging from the simplest telescopes in backyard observatories to the most complex spectrometers on advanced spacecraft.

NASA’s Solar Dynamics Observatory (SDO), launched in February 2010, made the finding:  About 1 in 7 flares experience an “aftershock.”  About ninety minutes after the flare dies down, it springs to life again, producing an extra surge of extreme ultraviolet radiation.

“We call it the ‘late phase flare,’” say NASA “The energy in the late phase can exceed the energy of the primary flare by as much as a factor of four.”

What causes the late phase? Solar flares happen when the magnetic fields of sunspots erupt—a process called “magnetic reconnection.”  The late phase is thought to result when some of the sunspot’s magnetic loops re-form. A diagram prepared by team member Rachel Hock of the University of Colorado shows how it works.

The extra energy from the late phase can have a big effect on Earth. Extreme ultraviolet wavelengths are particularly good at heating and ionizing Earth’s upper atmosphere. When our planet’s atmosphere is heated by extreme UV radiation, it puffs up, accelerating the decay of low-orbiting satellites.  Furthermore, the ionizing action of extreme UV can bend radio signals and disrupt the normal operation of GPS.

M0OXO On-Line Qsl Request System (OQRS) goes 'live'.....


I am pleased to announce that the new OQRS (Online QSL Request System) has gone 'live' today (18th Sept. 2011).

This should simplify things a lot and make requesting bureau and direct cards very easy for anyone to use. You,(as the user) will be able to go into the system after the request and you will see the status of not only the current request, but all the cards you have previously requested since the service began.

If you decide that you want the card Direct, then the facility allows you to request the card, pay for it in a variety of ways (via Paypal) and then you send your card via the bureau as normal. The requested Direct card will be with you in a very short and timely manner. Bureau requests are of course at no cost but the card will reach you in half of the time the bureau usually takes.

As mentioned above, there is of course a small charge for the Direct card which has to be made due to cost of postage, envelope and media etc but this is kept to a very minimum to make it easier on you. I can accommodate up to 20 qso’s on one card but to do this it would completely obliterate all of the necessary information on the card you require for your awards etc etc. I would suggest that 8 qso’s on a card is enough and then the card design, image and information is still legible but that’s a matter for you????

Please take a look at the system and see how it works but PLEASE, if you have already sent a card via the bureau then please do not send another request, email me to discuss the options.

73 es GL (feedback always welcome!), Charles

Kepler Discovers a Planet with Two Suns

kepplerThe existence of a world with a double sunset, as portrayed in the film Star Wars more than 30 years ago, is now scientific fact. NASA's Kepler mission has made the first unambiguous detection of a circumbinary planet -- a planet orbiting two stars -- 200 light-years from Earth.

Unlike Star Wars’ Tatooine, the planet is cold, gaseous and not thought to harbor life, but its discovery demonstrates the diversity of planets in our galaxy. Previous research has hinted at the existence of circumbinary planets, but clear confirmation proved elusive. Kepler detected such a planet, known as Kepler-16b, by observing transits, where the brightness of a parent star dims from the planet crossing in front of it. Scientists detected the new planet in the Kepler-16 system, a pair of orbiting stars that eclipse each other from our vantage point on Earth. When the smaller star partially blocks the larger star, a primary eclipse occurs, and a secondary eclipse occurs when the smaller star is occulted, or completely blocked, by the larger star.

This discovery confirms that Kepler-16b is an inhospitable, cold world about the size of Saturn and thought to be made up of about half rock and half gas. The parent stars are smaller than our sun. One is 69 percent the mass of the sun and the other only 20 percent. Kepler-16b orbits around both stars every 229 days, similar to Venus’ 225-day orbit, but lies outside the system’s habitable zone, where liquid water could exist on the surface, because the stars are cooler than our sun.


Strumblehead boys in 4W6A...(Day 16 Update / QRT)


cid_11092011339Well finally, several of our StrumbleHead DX Group start their journeys to Timor Leste today for the 4W6A Dxpedition on Aturo Island. Here is the final press release from Tim M0URX as they left the UK. I will keep this blog updated as and when I hear from them so please call in again and find this entry as I add more to it throughout the next three weeks. Scroll to bottom for latest updates

GOOD LUCK to all the Team, lets hope all goes well and it's a tremendous success, have a safe journey to all!

So what route will I be taking to get to Timor-Leste? After a two hour coach trip to London, Heathrow Airport, there is a seventeen hour flight to Darwin, NT, Australia Via Singapore. I will be traveling with Ant, MW0JZE. In Darwin we will meet up with VK8NSB, Stuie, (Team leader) VK8DX, Oliver & VK2IA Bernd, The following day we fly to Dili, Timor-Leste where we have some work to do gathering supplies, generators need to be picked up and checked, fuel, food, water all needs to be bought.

The bulk of the equipment, including the linear amplifiers, the Titanex V160E vertical, Hexbeam and other antennas, left Darwin, Australia, on 6 September. It has all arrived safely in Dili, Timor-Leste, and is now awaiting the arrival of the team next week.

9M6DXX and 9M6XRO leave Malaysia on 12 September for a transit stop in Bali, from where they plan to be active 'holiday style' as YB9/G4JVG and YB9/GM3OOK respectively. Unfortunately, due to a late change of airline timetable, they will not now arrive in Dili before the afternoon of Friday 16 September. The chartered boat taking the team and the equipment to Atauro Island has therefore been rescheduled to later that afternoon.4W6A-400x65

It is likely that only one or two stations will be on the air that day as the team will run out of daylight before all the antennas can be erected. The remainder of the antenna work will commence at first light the following morning (approximately 2115UTC on 16 September) and 4W6A should be fully operational by the morning (UTC) of 17 September.

4W6A will be QRV on all bands 10 to 160 metres, using CW, SSB and RTTY with up to four stations simultaneously. It is hoped that log search will be available, thanks to the Clublog facility (go to www.4w6a.com/qsl-information/log-search), but this is dependent on a reliable Internet connection being available on the island. Col, MM0NDX, is the pilot for 4W6A and is responsible for providing feedback to the team. He may be contacted at This email address is being protected from spambots. You need JavaScript enabled to view it. The QSL manager is M0URX, direct (SAE plus 1 IRC / $2), via the bureau, or LoTW. The entire log will be uploaded to LoTW as quickly as possible after the end of the operation or, if possible, also during the DXpedition. Direct or bureau QSLs may also be requested using the M0URX Online QSL Request Service (OQRS) at http://m0urx.com/oqrs (there is also a link from the 4W6A website at www.4w6a.com/qsl-information).


K800_13092011351Well after the heads up from the rest of the Strumblehead Team, Rob, Chris and I managed to worked both of the guys down in Darwin. Tim was signing VK8/M0URX and Ant VK8/MW0JZE. Sig around 1300UTC were poor with heavy Qsb but an hour later and after a frequency shift they peaked 5/8 with me which also gave Ants wife Laura the opportunity to get thro from her home station, great job!

Here is the latest report
from Tim 1400UTC 13th September);

After a long journey to Darwin Northern Territories Australia taking two days the plane finally touched down at 4.30am local time. Waiting for us at arrivals was Stuie, VK8NSB. We have spent most of the day acclimatising and making sure that we have no jet lag and have done this by staying awake all day and trying to keeping busy.

Stuie has shown us around Darwin today which we have really enjoyed.

This evening we met up with Oliver VK8DX we all had lunch together before retuning to the shack to finish off preparing the K3s and K2 for the RTTY and CW operators of the trip. Having had very little sleep in 40 hours, we are off to bed, catch you all tomorrow. Thanks also for all the guys that called in from the UK, EU and AS, great to have your support on the trip!

Weather is baking hot as you would expect and we have purchased our hats (see photo) for our trip to Aturo Island in a few days.

Thanks also for all the guys that called in from the UK, EU and AS, great to have your support on the trip!

73 from/OBO Team 4W6A (M0URX)


Bernd, VK2IA, arrived from Sydney on Wednesday afternoon in Darwin. With 5 members of the team now at Stuie's house we had a meal and talked about the work ahead of us over the next 12 days. It had to be an early night for all of us as we needed to be awake at 3am to leave Darwin, Northern Territory, Australia for a 0545 hrs local time flight with Air North to Dili, East Timor. It was in the departure lounge that the team met with the Timor-Leste, Prime Minister Xanana Gusmao our team leader VK8NSB Stuie had the chance to inform the Prime Minister of our DXpedition to Atauro Island. The team had a group photograph with the Prime Minister before boarding our flight.

The team were met at the Dili International Airport by Kim & Tony our local support team and driven to the Dili Hotel where the team members had various pre DXpedition shopping and logistics matters to deal with. The final two K800_part_4W6Amembers of the team are still in Bali, Indonesia prior to leaving for Dili on Friday. We had a meeting with Kim & Tony to discuss all the duties that we would need them to assist us with in getting the fuel over to the Island daily for the generators along with supplies for the team. The Hexbeam was delivered to the hotel, and the generators have been checked over for collection later.


Well the guys a little too busy today to give us any feedback, understandably they need to crack on with things at their side. I the meantime just a little addition to say that all is well and team arrived safely on Aturo Island. They have been very busy setting up and managed to get one station on the air around 10.45 UTC when they appeared on 21295.00. Signals were very good and gave a full 4 1/2 hours where the signals were 57 to 58 with me in Yorkshire (on my Hexbeam (MW0JZE build!). Tim, Steve and Ant were operating and had a huge pile-up resulting in a 5-20kc split at times. Tim and Oliver are concentrating on getting the Hexbeams up and we expect another update later today when they have time.

Well done guys, keep it up, a good start!



We have just received some news from Col, MM0NDX, the pilot station.

The team have lost one of the generators (possible breakdown) so they are limited with what they do at the minute. They are also hoping to get to the internet cafe to upload logs and get any news back to us here in the UK.

We will advise when more is forthcoming.

The first logs from 4W6A are now on line at http://www.4w6a.com/qsl-information/log-search.html


DAY 9 REPORT (.....troubles in Paradise Cry )

The guys had troubles with the 20M station yesterday evening with several reports of very bad audio. The Pilot tried to make contact but without initial success. We hope now the situation is sorted. Here are a few lines from yesterday which try to explain yesterdays events and dont forget to check the Logsearch (click here) although uploads may only be every few days due to local internet and access issues;

''The main reason why contacts have been a little slow is that we had a malfunction with a transceiver, particulary on RTTY & SSB. We are now running without back up.

Due to a power failure not all the logs synchronised all QSO's logged for the upload. They are all showing on the network but did not all download. This will be rectified on next download/upload

Currently the team are experiencing difficulties on the 75/80M band from a yet unknown source. They will be back on 80M tonight (19th),or earlier if the issue is resolved, looking to work North America. Also, the generator issues are still hampering the team, so limited stations are the order.

As mentioned above, even now at 1530UTC there is still an issue with uploads to the 4W6A DXpedition log, there are qso's missing, but this DOES NOT mean you are NOT in the log. Hopefully, the problem will be resolved soon, but if in any doubt, please work 4W6A again. The team are working hard to get these jobs sorted but those of you who have been on these trips will realise how difficult it can be when you are in a foreign place without the comforts of home, please be patient!



The problems the team had with the audio on the 20M station rig was finally resolved yesterday. A chat with a team member said that it was in fact an issue with one of the K3's but after a full reset to 'factory defaults' it seemed to cure the problem. Up to yesterday evening (19th September) the team had logged just short of 15,000 qso's - Great job!!!

Further from the team (1030am UTC);

Next log upload in few hours. Partial log uploads only, due to generator issues. Feel free to work them again if you wish to confirm the band slots. The Internet is so unreliable, almost to the point of unuseable.

They will be QRV on 80 and 160 tonight for EU but still a very high noise level on 80, moreso than 160 which at this stage cannot be resolved.

Many thanks to everyone for their kind words and support in the last few days of problems.


From Atauro;
Conditions continue to be good, though perhaps not quite as spectacularly good as on 16 and 17 September. As of 1130UTC today, 20 September, 4W6A has made approximately 18.5k QSOs.

We are aware that approximately 1000 CW QSOs made on the morning of 18 September on 20m and 30m are missing from the online log on Clublog. We hope to include these QSOs in future log uploads, but to be absolutely certain of a 'good QSO' you are invited to make another contact if you cannot find your call in our online log.

Last night was the first night without any local noise on 160m, and over 250 QSOs were made on topband to North America, including some East Coast contacts, to Europe as far west as the British Isles, and to Japan.  We should be on 160m each night now until 25 September.

We have received some reports of poor modulation quality on one of our SSB stations. We appreciate the feedback: the problem has now been solved. It would seem that the audio settings of one of the K3 transceivers had mysteriously changed in transit and we have now reverted to the factory default settings




This message was recieved from the Team yesterday as major problems were still being made as more qso's were uploaded. Yesterday for example, the 12M qso's from the previous day were all OK in the Logsearch. After the next upload however later in the day, most of the 12m Qso's were overwritten and NONE showed in the log.
PLEASE be patient. They guys are aware of the problem and the Pilot has hundreds of emails complaining about missing qso's. We have problems even contacting the team so as you can imagine, ammending logs is not possible at all at the moment. We understand that the main log is fine and the fault is with the partial updating. The full logs will be updated as soon as they have a stable internet connection and then we expect all the issues to be resolved;

'''16:36 UTC 23/09/2011

It would again appear a problem with uploading logs from the jungle has taken place. We are attempting to establish comms with the team to ascertain exactly what the problem is, but for the moment we suggest all ops with "missing QSO data" keep details of your contact(s). As soon as we clarify the issue, the 4W6A website will be updated. '''


Initial reports saying 4W6A QRT at 0200UTC today were incorrect. They have 40,200 QSO's logged at 1500z.
Most of the antennas are now done with just 12 and 15m dipoles remaining with one station.
Internet problems have plagued the team the past few days so next log upload will be completed when they arrive in Dili tomorrow.


The team of 4W6A have left Atauro, and are spending two days sampling the atmosphere and culture in the City of Dili. Two members are on their way home, John, 9M6XRO, and Steve, 9M6DXX.
The final log for 4W6A is online via this website, please be wary that until a stable connection is available, that some data may not be apparent.

The QSL requests are flooding in, and the comments received are wonderful, the dxpedition has been received amazingly well
especially some of the teams 160M operation. Hopefully soon, we will be able to post some pictures from Atauro, to give you a chance to see where the team operated from.

73 from/OBO Team 4W6A


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