January 18, 2005
The Ice Dance - Collision of B15A
I've blogged twice now about that wayward havoc-wreaking iceberg, B-15A, first when it was menacing penquins and researchers in the McMurdo Sound, and again when it was threatening to put on a show by colliding with an "ice tongue" extending from a larger glacier. Well the "show" has commenced, and I've pulled some satellite images down an put them into a format where this extraordinary event is easier to witness, please follow on into the extended entry to see the "Ice Dance".
Oh yeah, don't miss the animation at the end, I contacted a photojournalist down at McMurdo and he was gracious enough to put it up for us.
The "Collision" as viewed from space.
All Images courtesy of NASA's MODIS Rapid Response System.
The first image we have was taken on January 3rd, B15A is clearly visible and looks remarkably like a very large American-style Aircraft Carrier.
UPDATE: It should be noted that in reality, no "collision" has taken place. Rather the presense of B15A is altering currents, which is, in turn, causing this activity. Thanks Brien Barnett.
Images from Jan. 4-8 are obscured by cloud cover and don't really give much indication of what's going on, but I won't leave you hanging, if you want to see the raw images from NASA, here they are, Jan. 4, Jan. 5, Jan. 6, Jan. 7, Jan. 8.
Then on the 9th there's a break in the cloud cover and we can see that the show has begun, through the clouds at the top left edge of the berg, you can see where it's altered the currents in the area and is busting up the "fast ice" or "sea ice" that forms in the winter. I've been told that this is not the ice shelf, which is thousands of feet thick but rather this "fast ice" that's ten's of feet thick. This ice forms every winter and breaks up in the Antarctic summer (now) it's possible that B15A has altered the currents in the region keeping this ice close to shore in the sound.
More cloud cover on the 10th, but you can still see more of the "fast ice" is breaking up.
Clouds on the 11th, but here is the raw image.
On the 12th we get a break in the clouds, and the picture is quite stunning.
On the 13th, we see the "tongue" more clearly and the fractures beneath the tongue as B15A approaches.
Clouds move in on the 14th, but luckily, the snapshot from space is just before the clouds obscure the site. Keep in mind that B15A is 80 MILES LONG.
Images from the next three days shows further break up of the "fast ice". It also shows part of the ice tongue beginning to break off.
Finally, today's image looks as if the currents are changing and B15A is starting to move away a bit. The majority of the tongue seems to have dodged a rather big bullet for now. It should be noted that the smaller round berg that is breaking away from the tongue has been named B16J.
The danger to this ice structure isn't over yet, and I'll keep watching it. NASA says that the currents in the area will cause this process to repeat itself as B15A moves away only to circle back. I guess B15A is just eager to give this tongue a lashing (horrible pun, I know).
I'll update this entry over the next few days or until the action is over. Ain't it cool tho'!
UPDATE: Brien Barnett, a photojournalist down in Antarctica and I have exchanged a few brief emails and he's providing a Quicktime Video of the MODIS images and the journey of B15A. Click here for the movie.
Posted by JasonColeman at January 18, 2005 1:26 PM