Pre-JIRP Readings: Rapid Wastage of Alaska Glaciers and Their Contribution to Rising Sea Level

For this blog post, we'll provide some key points to think about rather than the questions as in previous posts.  We look forward to some stimulating discussions in Juneau!

The reading this week is as follows:

Arendt, A.A., Echelmeyer, K.A., Harrison, W.D., Lingle, C.S., Valentine, V.B., 2002. Rapid Wastage of Alaska Glaciers and Their Contribution to Rising Sea Level. Science 297, 382–386.

Alaska represents only a small fraction of the world's glacier ice, but is among the largest sources to new water contributions to sea level rise.  To understand why, think about two buckets filled with the same amount of water.  Its a hot sunny day, and you and the buckets are hanging out in a parking lot. You trip over one bucket and spill it on the ground.  That spilled water will evaporate much more quickly than the water in the bucket, in part because the surface area to volume ratio has changed.  This is a good analogy to why Earth's mountain glaciers have more rapid rates of change than do the ice sheets. Climate and geography play a part as well, but this is a good place to start when thinking about differences between glaciers and ice sheet mass balance.

Another aspect to consider as you read this paper are the research methods used and possible errors associated with them.  All methods have errors, which can significantly impact research results.

That's all for today.  See you all soon!

Pre-JIRP Readings: IPCC AR5 Summary for Policy Makers

These questions come to us, again, from both Dr. Shad O'Neel and Dr. Jeffrey Kavanaugh and are related to the second reading on the required pre-JIRP reading list. Please read, reflect, and provide your input in the comments section. 

From Dr. O'Neel:  How does the confidence presented in IPCC AR5 SPM compare to public perceptions of climate change?  What do these venues base their positions on?  Do you feel that the claims made in the SPM are well-justified?

How does glacier change contribute to the global sea level budget?  Summarize the different components of this budget, and identify any common misperceptions that are associated with sea level rise. Why are ice dynamics (what are ice dynamics) important to sea level budgets?

This document is loaded with statements that end like this: {6.5, 7.7} which are references to the full IPCC report available here: http://www.ipcc.ch/report/ar5/wg1/ 

We encourage you follow at least one of these linkages to explore a topic of interest to you in greater detail. 

From Dr. Kavanaugh: Shad offers good questions here. I will just add to/clarify one of them: The authors of the IPCC AR5 state that that "Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia." Briefly summarize the distinct lines of evidence drawn upon to support this conclusion.

We hope that in addition to your readings, you are staying active and keeping up your fitness so that you arrive in Juneau ready to go! Cardio and core work are both important.

 

Pre-JIRP Readings and Discussion Questions

JIRP has rolled out some pre-expedition readings to students participating in the 2015 field season. We have heard from students in past years that they wanted more content before the season begins so we have answered that call and will be posting both discussion/reflective questions and details on student projects here on this blog. Over the next 11 weeks, students will be able to check here for the weekly post which will either pose questions on your readings or give you a detailed outline on one of six student projects on deck for this summer.

We encourage students to begin the process of engagement by participating in the discussion in the comment section. You will have a chance to ask questions of the Principal Investigators on the student projects and start learning from one another.

The questions this week are posed by two of our faculty and relate to your reading of Post and LaChappelle, Glacier Ice.  Students were asked to READ THE TEXT of this coffee table book.  

Our first set of questions are from Dr. Shad O'Neel. "Image 38 in Glacier Ice shows the 'three congruent glaciers'. We often talk about how climate is a principal control on glacier mass balance (glacier health) - aren't they supposed to be the 'canary in the coalmine'? How can the behavior in this image be explained? What is a less obvious control on the health of these glaciers? What are some other controls that may not apply to all glaciers but certainly produce examples that buck the mainstream trends?"

Our second set of questions are from Dr. Jeffrey Kavanaugh. "A defining characteristic of glaciers is that they move, slowly making their way down slope under their own immense weight. This motion is evident throughout the photographs presented in Glacier Ice and includes both viscous behaviors (where ice flows like a thick fluid) and brittle behaviors (where ice fractures like a rigid solid). What features visible in the photographs demonstrate these two forms of motion? Under what conditions or in what areas does flow appear to be fluid-like? Where do brittle behaviors seem to dominate?"

 Photo by Ben Partan

Photo by Ben Partan