Tuesday, November 26, 2013

Mount Baker Glacial Ice Loss

Don Easterbook is worked up by a recent Bellingham Herald article by John Stark on a presentation to the local City Club monthly talk by Michelle Koppes letter-to-weeditors-some-cold-hard-truth-about-our-local-glaciers.html.

I have little interest this time in whack-a-mole with Easterbrook's graphs (see below), but Easterbrook takes issue with a statement Koppes made about our local Mount Baker glaciers,  "Koppes claims that "glaciers on Mt. Baker…..have lost 20 percent of their volume since 1990."  This one is mind-boggling! Keeping in mind that glaciers thicken rapidly upvalley from their terminus, the total amount of ice loss since 1990 can’t be more than a few percent. Other glaciers show the same relationship. How any competent glaciologist could come to such a conclusion is hard to imagine."

Koppes was referencing an ongoing study program that has been taking place on North Cascade Range glaciers including three on Mount Baker over the past for 30 years. Measurements indicate that indeed the loss in ice volume on the three Mount Baker glaciers since 1990 is 15 to 20 percent http://issuu.com/mspelto/docs/mount_baker_glaciers or for the journal article http://onlinelibrary.wiley.com/doi/10.1002/hyp.9453/abstract.

As for competent glaciologists reaching such "hard to imagine conclusions", I would suggest making measurements works pretty well.

It has been fortunate for Washington State to have Marui Pelto working on our North Cascades glaciers over the past 30 years. His latest yearly summary  http://glacierchange.wordpress.com/2013/09/01/north-cascade-glacier-climate-project-2013-field-report/.

I've posted on Don Easterbrook before



Jill said...

Well said and all of the mass balance data we have collected, which is volume after all, goes to the World Glacier Monitoring Service, of which I am the US National Correspondent.

Dan McShane said...

The above comment was from Mauri Pelto via his daughters computer.

Doug Clark said...

Nice post, Dan. Don's comment about glaciers thickening rapidly upvalley highlights his lack of understanding of basic glacial dynamics; glaciers may thicken rapidly upvalley when they're advancing, but typically are much thinner below the equilibrium line when retreating (as they are now). The volume of ice-loss is much greater than simply considering the change in glacier terminus position. Ironic coming from someone professing expertise as a glaciologist.