Team Member Profile: Seth Campbell!

Hi Friends,


This post was scheduled before we left McMurdo. We do not have internet access in our field camp!


Our last week in McMurdo, I asked my teammates to respond to a few questions about their fieldwork and camp life. Here are Seth's responses! Check out our archives and future posts for entries from our other team members!


What will your focus be while you're out in the field?

My goal for this project is to collect ice penetrating radar data.  We use this data to:

1. Measure glacier ice depths at each study location, and
2. Determine the amount of ice deformation that has occurred at each study site.

Glaciers form through year-after-year snow accumulation with minimal melting. Each snowfall event piles onto the previous layers, similar to a stack of pancakes.  In the stack, the oldest layer is on the bottom and the most recently deposited layer is on the top. Eventually, the compressed, deep snow condenses to form ice and the ice will begin flowing very slowly downhill as a result of gravity.  This “flowing” causes the internal layers of the glacier to deform.  What is deformation?  Take a common fun household item as an example:  Play dough or silly putty.  If you hold a roll of silly putty or play dough in your hand and squish it the roll changes shape.  This shape change is an example of deformation.  The flowing nature of ice caused by gravity is one example of how ice can deform.  We use ice penetrating radar to determine such details as ice depth and the structure of the internal layers formed through the many years of snow accumulation and ice flow.  Glaciers that have nice flat lying layers suggest that the ice has moved very little over time whereas glaciers that have all kinds of structural complexities imaged with radar suggest that a significant amount of ice flow and deformation has occurred.   

Kevin Volkening towing an ice penetrating radar system on a glacier in Alaska with the transmitter and receiver visible.  The computer that records the data is out of the picture (arrow; photo: Seth Campbell). 

In the 2010-2011 field season for this project, we collected 122 km of ice penetrating radar data using equipment owned and on loan from Dartmouth College (courtesy of Dr. Bob Hawley) and the Army Corp of Engineers Cold Regions Research and Engineering Lab (courtesy of Dr. Steven Arcone).  We plan to collect a similar amount of data during this (2011-2012) field season.  The complete system includes an antenna transmitter that sends electromagnetic (EM) pulses through the ice and an antenna receiver that receives the reflection of each EM pulse from layers in the ice and bedrock under the ice.  The antenna is connected by cable to a computer which records data about each EM pulse sent and received by the transmitter-receiver combination.

Diagram of EM pulses sent from the transmitter and being reflected off internal layers in ice.  The reflections are recorded by the receiver and computer for future study (Figure: Seth Campbell).

SIMPLE INTERNAL DEFORMATION - Not a lot of internal layering:

Example of a radar profile collected on a glacier that has had very little deformation from ice flow.  Note the many flat lying internal layers suggest that this ice hasn’t been deformed much at all (i.e. very slow or little ice flow or other mechanisms to deform the ice). (Figure: Seth Campbell)

COMPLEX INTERNAL LAYERING - LOTS of deformation!

 Example of a radar profile collected in Antarctica that shows significant ice layer deformation from ice flowing and likely other mechanisms;  the boundary between the light color and the dark color at the top of the image is the ice surface (Figure: Seth Campbell).

Example of a computer generated ice depth model using radar data collected in a grid pattern over a valley glacier in Alaska (Figure: Seth Campbell).

Last season, the collection process required a team effort.  We towed the antenna behind a snowmobile at rates between 3 and 8 km per hour.  For comparison, the average human walking speed is 3-5 km/hour, so we move VERY slow as far as snowmobile travel goes!  We travel slowly to assure that we won’t break the equipment over the rough glacier surface.  We also travel slow to improve the contact between the ice and the antenna.  If the antenna isn't touching the ice (i.e. if we were driving fast and the antenna bounces along the surface), then much of the EM pulse we are attempting to send through the ice reflects off the ice surface instead of penetrating it.

What is your favorite part about being in the field?

Hmmmm… tough question!  I love being in remote glacial and mountainous areas.  We found a note on top of one of the mountains we hiked from previous visitors in the year 1962 (I think)!  This isn’t to say that no-one has been to this site since 1962… BUT very few people get to go to these places and I think it’s a pretty special opportunity to visit such a remote and spectacular place.  Besides that… on these trips you really get to know your coworkers well because of the small team and close living conditions.  I’ve figured out that often times your ‘co-workers” end up being some of your best friends through the years.  We have an AWESOMELY fun team.


What is your favorite camp meal?

Do no-bake cookies that Kat makes, count?  I can certainly make a meal out of them!  And of course hot apple cider drink mix… for an actual meal I think the Cornish game hen was pretty awesome last year!

What do you miss the most while you're out there?

Of course I miss my wife, Kristin, the most, especially during the holidays! (I hope she reads this!) I also obviously miss my family and friends very much. Outside of that, I miss ice cream!

Many thanks to Seth for providing today's guest entry! We miss you guys back home! Thanks for checking in with us,


Claire