17 April 2009

from WatsUpWithThat Website

 

 

Those masters of disaster are at it again, and it appears our friendly scientists at that National Snow and Ice Data Center (NSIDC) help this story along each year.

Thanks to WUWT (What'sUpWithThat Website) reader Ron de Haan who spotted this on "Antarctic Sea Ice - Wilkins Ice Shelf".

Note the dates for these two stories are a year apart, but use the same photo.

 

 

 

 

It seems that not only is the photography recycled, so is the storyline. It seems to happen every year, about this time.

 

Note the photos show shear failure and cracks, not melted ice. Shear failure is mostly mechanical-stress related, though ice does tend to be more brittle at colder temperatures.

National Geographic reported this story headline last year, March 25th 2008
 

 

 


PHOTO IN THE NEWS

Giant Antarctic Ice Shelf Collapses

 

 

 

 

Don’t let the date in the upper right fool you, that's just an automatic “today’s date” javascript element found in many webpages.

From the Nat Geo story:

“[It's] an event we don’t get to see very often,” Ted Scambos, lead scientist at the U.S. National Snow and Ice Data Center in Boulder, Colorado, said in a press statement.

Now, how is it that an ice shelf breaks up in the spring of 2008 and again in the spring of 2009 and it’s “not very often”? Hmmm...

It seems NSIDC’s Ted Scambos gets around. Doing a Google search for Wilkins ice shelf + “Ted Scambos” yields about 4,930 results. Yep, he sure gets the word out every year.

Ted Scambos said something similar in 1999:

“On the southwest side of the peninsula, the Wilkins ice shelf retreated nearly 1,100 square kilometers in early March of last year [1998], said Scambos… Within a few years, much of the Wilkins ice shelf will likely be gone”

(Antarctic Ice Shelf Break-Up Accelerates)

But, as can be seen from the following January 1996 and March 2008 images, there has been hardly any change in a decade. Look at the photos below from the appinsys web site:

 

 

 

 

But wait, there’s more examples of that “not very often” Wilkins ice shelf breakup, again from the appinsys web site:

As the following historical satellite images of the Wilkins Ice Shelf show, the disintegration/re-growth is an annual event (winter ice re-growth season; summer melt season).

 

Wilkins Ice Shelf Dec 1993

Wilkins disintegration in Feb 1994

Wilkins in Oct 2004, on the mend

Wilkins in Mar 2004 - breaking up again

Wilkins in Nov 2008 - icing up

Wilkins in Feb 2009 - uh oh!

 


But we just know warming is involved, NSIDC says so:

The MSNBC 2008 article reports on a NSIDC article which states:

“NSIDC Lead Scientist Ted Scambos, who first spotted the disintegration in March, said, “We believe the Wilkins has been in place for at least a few hundred years. But warm air and exposure to ocean waves are causing a break-up.”

The closest station to the Wilkins Ice Shelf in the NOAA Global Historical Climate Network database is Rothera Point.

 

The following figure shows the historical data for Rothera Point, with monthly temperatures in blue and the annual January temperature in red. Summer (Dec–Mar) temperatures have not increased – the 2000s January temperatures are similar to the 1940s (the oldest data available).

 

So why does NSIDC’s Scambos blame it on air temperatures?

 

 

 

 

The appinsys article goes on to talk about ocean currents and sea surface temperatures being a contributor, and it is worth the read.

The real question is, how often are we going to see the Wilkins Ice Shelf be a lead news story as poster child for “global warming” to illustrate ice loss in Antarctica that is actually growing.

I guess as long as we have NSIDC’s Ted Scambos to help the media, it will be “something we get to see fairly often”.