Howard Nunataks GPS and seismic station maintenance, 01 Jan 2014.

The new GPS station installed at Pirrit Hills Antarctica on 30 Dec 2013.

We spent the day training how to rescue ourselves or someone else if they fall into a crevasse – especially important to brush up on this since we intend to install six new GPS stations this year and so will be exploring some new territory, not just visiting sites where we’ve been before.

Trip to upgrade equipment at the Mt. Coates GPS station on 23 Dec 2013. We flew from McMurdo in a Bell 212 helicopter and returned after about five hours on site.

Bell 212 helicopter, 36J, returns to Mt Coates to pick us up.

Rip’s comment about Malamutes got me thinking about how many dogs we would need and how long it would take to haul our ourselves, our equipment, and our fuel from McMurdo to Union Camp by dog sled (By the way, we have used dog sleds to reach a GPS station in Greenland). We have 22,000 pounds of equipment, 36 drums of JP8 (jet fuel) at 450 pounds per drum, and 7 people at about 250 pounds per person including survival gear. That’s a total of 38,950 pounds. The distance is about 1300 miles. If a dog can cover 20 miles per day in Antarctic conditions and each dog can pull 150 pounds, then we need 260 dogs and 65 days ! That’s a conservative estimate since none of us has much experience driving dog sleds !

(Photo credit: http://www.southpolestation.com/trivia/igy1/61tcw.html)

Map showing our project’s GPS and seismic stations. I’ve drawn a red line around the area where we will be working in the next few weeks. Union Glacier Camp is shown by a red star over on the left. McMurdo Station, where I am now, is marked by a gray star at the bottom right corner of the map, just left of Mt. Coates. Our helicopter flight to Mt Coates was cancelled again today due to fog. We’ll try again on Monday.

The 2011-2012 POLENET season is underway and off to a great start. This year the team will be working out of McMurdo Station, Byrd Camp, and ALE Union Glacier Camp in order to install 4 GPS sites, remove 13 seismic stations, and maintenance 31 GPS and 22 seismic sites throughout the West Antarctic ice sheet. The sites that are serviced will continue to operate and collect data for another year. Many of the sites will be reached through use of either a Basler or Twin Otter airplane, but this season there is also a skidoo traverse that will travel along the temporary seismic array for up to 2 weeks at a time to remove stations.

From left to right: Cristo Ramirez, Dr. J.P. O’Donnell, Mike Roberts, and Andrew Lloyd preparing to leave on the southbound section of the seismic traverse to remove temporary stations.

Photo credit Dr. Douglas Wiens

___________________________________

From left to right: Dr. Douglas Wiens and Mark Whetu helping to load equipment removed from the temporary seismic station ST01.

Photo credit Dr. Brian Bagley

___________________________________

From front to back: Mark Whetu and Dr. Pippa Whitehouse helping to dig out temporary seismic station ST09.

Photo credit Rachel Gesserman

___________________________________

From left to right: Brian Harrison, Paul Carpenter, Dr. Brian Bagley, Abigail Sussman, and Alex McCorquodale removing temporary seismic station ST10 from the seismic transect.

Photo credit Betsy Spencer

___________________________________

From left to right: Dr. Douglas Wiens and Dr. Brian Bagley getting ready to dig out equipment and collect data from Byrd seismic station. This station will be revisited later in the season to install a Xeos Iridium modem in order to monitor the station’s state of health and to make it part of the permanent POLENET array. 

Photo credit Paul Carpenter

___________________________________

From left to right: Rachel Gesserman and Paul Carpenter beginning to service seismic equipment and collect data from Siple Dome station.

Photo credit Dr. Pippa Whitehouse

___________________________________

After a long day of digging, the Upper Thwaites Glacier seismic station was partially rebuilt to continue collecting data for another year.

Photo credit Rachel Gesserman

___________________________________

Dr. Terry Wilson helps service the Wilson Nunatak GPS station. Besides ensuring that the stations will continue to run for another year, Dr. Wilson also investigated the bedrock at each site she visited.

Photo credit Jeremy Miner

___________________________________

Pecora Escarpment GPS station after being fully serviced and left to record data for another year. The station is at the edge of an abrupt cliff, requiring personnel to harness themselves to the rock while working.

Photo credit Jeremy Miner

___________________________________

Howard Nunatak GPS station after servicing, with both the seismic station and twin otter airplane visible in the background.

Photo credit Jeremy Miner

___________________________________

The Mt. Suggs station is traditionally damaged by wind and bad weather. This year the station had to be rebuilt in order to continue running for another year, which required the replacement of 22 batteries.

Photo credit Jeremy Miner

___________________________________

On top of this quartzite outcrop with a great view of the Duffek Mountains, the Cordiner Peak GPS station was serviced with standard maintenance procedures and left to collect data for another year.

Photo credit Jeremy Miner

___________________________________

The Haag Nunatak GPS station had 2 destroyed wind turbines. Although only one was replaced, solar power will help to keep it running for another few years.

Photo credit Jeremy Miner

___________________________________

From left to right: Mark Whetu and Dr. Eric Kendrick helping to install the Lepley Nunatak GPS station. After four years of trying to build this site and being unable to due to bad weather, the station is finally complete.

Photo credit Jeremy Miner

___________________________________

From left to right: Mark Whetu and Dr. Eric Kendrick helping to install the Lepley Nunatak GPS station. After four years of trying to build this site and being unable to due to bad weather, the station is finally complete.
Photo credit Jeremy Miner

___________________________________

It has been almost 2 weeks since I arrived at Byrd camp in the middle of the West Antarctic ice sheet and our project is off to a great start. The camp itself is pretty remote and home to about 35 people. This includes the scientists working on the POLENET project, pilots from Kenn Borek Air who fly the Twin Otter and Basler airplanes to our seismic and GPS sites, and a hard-working camp staff made up of weather observers, kitchen staff (who happen to be excellent cooks!), and people who do daily tasks around camp. You can probably imagine with only 35 people, the camp is not too big. There are several semi-permanent tents that house the galley, washroom (aka Byrd Bath), science equipment, pilot sleep quarters, and a meeting tent where we can watch movies and hold science lectures. There is also a big plot of mountain tents where everybody else sleeps called “tent city” that is further away from some of the loud, heavy equipment used at camp. 

One challenging aspect of working here is figuring out what GPS and seismic sites to fly to each day. The process is a little tricky because in order to fly, the weather must be good at Byrd camp, at the site we are flying to which can range from 100-600 miles away from Byrd, and at a fuel cache along the route if the plane needs to re-fuel during the trip. If the weather forecast does not look good at any of these places, we cannot fly for safety reasons. Another complication is that the weather in Antarctica is rapidly changing, and the plan that we develop each night for where we want to fly can often change in the morning when the pilots get an updated forecast. This makes for some hectic mornings of getting the right people and equipment organized to fly because the planes can only hold a certain amount of weight and the equipment needed varies from site to site. Since I have arrived we have been able to visit 5 seismic sites. Some are only temporary stations that have been fully removed, and others we are collecting data from and performing maintenance on to keep them running for another year. Although the setup of a seismic site may not look like much on the surface of the snow, inside all the buried boxes is an intricate setup of equipment that will record earthquakes from around the world. The following picture is of a temporary site that we had to completely dig out and remove.

On the right side of the photo you can see a circular red dome. Under this dome is the actual seismometer, which is insulated in a foam box. Burying the sensor helps to keep out a lot of unwanted noisy signal created from wind because it is shielded by the dome and the snow. The sensor is extremely delicate and sensitive, and is composed of three masses in a spring-like system. Each mass is positioned differently in order to record ground motion in the east-west, north-south, or up-down direction. You can’t see it, but there is a cable running from the sensor through the snow and into the orange box on the left side of the photo where it is connected to a piece of equipment called a datalogger. The datalogger records these mass movements as digital data that can be viewed on a computer. Several times a day, the datalogger will transfer the digitized data to a small box called a baler that contains memory sticks. When we visit a seismic site, we can remove the baler to get all of the seismic data recorded over the last year or two. 

But how do we keep this station powered up and running all year long in the harsh Antarctic weather? In the back of the station photo is a set of three solar panels. There is a cable running from these solar panels through the snow and into the orange box where it is connected to a power module. The datalogger that I discussed before is also connected to this power module, along with 10 car batteries. During the 6 months of sunlight in Antarctica, referred to as austral summer, the solar panels charge the car batteries that provide power for the station. During austral winter when there is no sunlight, the batteries provide enough power to keep the station running. Just for comparison, when we install sites in other parts of the world we only need 1 car battery because the solar panels receive sunlight every day. You also might notice an antenna on top of the solar panels. This is a GPS antenna that is extremely important because it allows the station to know the exact time. The timing needs to be accurate to about 1/100 of a second; otherwise our data will be useless because we won’t know how long it takes seismic waves from an earthquake to reach the station. But when everything is set up correctly and functions without a problem throughout the year, we get excellent data like this signal from the March 11, 2011 Japan earthquake recorded at one of our seismic sites called Siple Dome. You can see how the earthquake looks on the up-down, north-south, and east-west components of the seismometer. We can use this data along with data from many other earthquakes around the world to make a map of the structure of the earth beneath Antarctica.  Here’s hoping that the rest of our data collected this season looks as good! 

After boarding three commercial flights, one Air Force C17, and traveling for about 33 hours, I finally arrived in one of the most remote places on Earth – Antarctica. For the next five weeks I will be based out of a small field camp in the western part of the continent called Byrd (named after the great Antarctic explorer Richard Byrd) to begin working on part of a project called POLENET, or the Polar Earth Observing Network. This particular project involves collecting GPS and seismic data that will help answer questions about the structure of the continent, the behavior of the Antarctic ice sheet, and how these may be related. My role will be to work primarily with the seismic instrumentation in West Antarctica, helping to collect data and perform any necessary maintenance on already installed instruments.

You may be thinking this all sounds interesting and exciting, but how exactly do earthquakes help us learn about the structure of Antarctica? Seismology is not strictly the study of earthquakes. Seismologists also use seismic waves from earthquakes to study the Earth. Just like an X-ray will expose details of the body invisible to the human eye, the behavior of seismic waves expose details of the Earth from the shallowest crustal layers all the way down to the core of our planet. When an earthquake occurs, there are several types of seismic waves that propagate through the Earth and are recorded at seismic stations. These waves move at different speeds depending upon what type of material they are traveling through. For example, a seismic wave will slow down when traveling through warmer layers. Seismologists can figure out how fast a wave is moving through different parts of the Earth by looking at the wave arrival time at a variety of seismic stations. The denser the instrumentation, the more detail can be observed about the underlying structure. By installing seismometers in Antarctica, we are able to figure out how the crust differs throughout the continent. 

Why do we care? It is important to understand the interaction between the ice sheet and the underlying bedrock. Think about placing a heavy weight on top of a thick sponge. The weight will create a depression in the sponge. But what happens when you remove this weight? The sponge will bounce back to its original shape. The Earth’s crust behaves in a similar way, but areas of warm, weak crust depress much more than areas of strong, rigid crust when put under the same weight. As the ice melts and relieves some of the weight on the continent, the crust begins to move vertically like the sponge and is detected by the GPS instrumentation. By combining seismic data about the type of crust beneath the ice with the GPS data showing the amount of vertical motion each year, a more accurate calculation can be made of the amount of ice that is melting and how fast it is happening. This rate of melt has a direct impact on sea-level change. In a time when global warming is a hot topic in science, it is important to figure out how the polar regions of the world are being affected and what that may mean for the future.

Before I can travel to Byrd field camp, there are a few things I need to do to prepare for the extreme environment I’ll be living in. I have spent this past week at the US base McMurdo going through different training courses, including a snow school that is referred to around here as “Happy Camper”. This hands-on two day training began by re-locating to the outskirts of McMurdo, conveniently far enough away to discourage those who may have thoughts of walking back to the cozy base. Throughout the course we learned skills like how to use camping stoves, set up tents, build snow walls to shelter our tents from the wind, build survival trenches for emergency situations, and how to operate a high frequency radio which we tested by calling the South Pole station. Although some of the more adventurous people chose to sleep in their survival trenches, I chose to stay in a tent and learned some good tricks for keeping warm in the process. By putting two bottles filled with hot water inside my sleeping bag, I was very comfortable throughout the night and could also keep my hat, gloves, and neck guard warm for the next morning. To wrap up the training we ran through some scenarios, including how to find a lost team member in the event of a white-out. This involved wearing white buckets on our heads so we were not able to see anything, which I’m sure is always entertaining for the instructors. The camping experience was surprisingly very enjoyable, especially because I had the opportunity to meet a lot of other scientists and learn about some interesting projects taking place in Antarctica. In the end I’d say I was a very happy camper and am ready to head to Byrd! 

Join us for the unprecedented! Three planes in one day! Check out our latest progress across West Antarctica and get a taste for life here at Byrd Camp.
To see a higher resolution version and download this podcast, please visit http://polenet.org/education/2minutes/

POLENET_8_xsmall.mp4
Watch on Posterous