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January 19, 2004

Franklin Island

Another day, another adventure. Today, I went with a science group to Franklin Island.

Going to Franklin Island is partly cool because we have to fly over open water. The usual helicopter folks, PHI (Petrolium Helicopters Incorporated) can't fly over open water down here, so we flew with the Coast Guard. Several Coast Guard helicopters with crew arrive around early January every year with the icebreaker, which is another story. In brief, the story goes: two Coast Guard icebreakers (big ships designed to break through sea ice by riding slightly up over it and crushing it under the weight of the boat, repeatedly, again and again, and back up and do it again, which makes for slow but often effective progress) come down every year in early January to break a channel through the sea ice to McMurdo so that other ships--most importantly, the vessels which come in to resupply and fuel McMurdo for the following year and to take out the past year's waste and other goods such as our GPS instruments--can make it in to the ice pier built next to town.

How did I get on this tangent?

Coast Guard. Helicopters. Us.

We left around 9:30 for Franklin Island. We arrived there about an hour later.

Franklin Island is baren, rugged, and volcanic. Obviously volcanic. Screaming volcanic. Except that it's no longer active.


[A closer view of the reds and browns of volcanic rocks exposed at Franklin Island.]


We were there to do GPS.

[GPS antenna on Franklin.]


[Jane and Sarah at work.]

The project is a collaboration between Ohio State University, USGS, and LINS (Land Information Systems of New Zealand). They are using GPS to monitor crustal motions related to glacial loading and tectonics. The tectonic story to me is the interesting one; they are trying to understand rifting, or crustal thinning/spreading in this area. The rifting is probably responsible for volcanism at Erebus and the other active volcanoes on this side of Antarctica.


[Mike takes notes amidst signs of a violent past.]


[Layers of volcanic deposits.]


A close-up of the layers. Note the green rocks in the mixture. These layers represent rubble blown violently from the volcano during eruptions past. Included in this rubble are these green rocks which stand out like sore thumbs--only prettier.


[Close-up of the green rocks which have been incorporated into the black, volcanic rock.]

The light green is a mineral called olivine, and forms in rocks high in iron and magnesium. Olivine is common in rocks derived directly from melted mantle, the layer beneath the Earth's crust (= deep within the Earth), but can also form in a shallow magma chamber and settle out of the melt. These rocks on Franklin Island may represent pieces ripped up from the bottom of the magma chamber.


Icebergs are cool, too.

Almost too much excitement for one day. Jane had to force herself to calm down. Way down. She calmed so far down that I was able to take this last shot when we'd already landed.

Posted by beth at January 19, 2004 9:05 PM

Comments

more awesome pictures! it seems that gps is allowing you to learn more variety in geology than if you were working as a geologist on a project. there definitely are perks to being a geophysicist!

Posted by: wilma - mother of beth at January 20, 2004 6:17 AM

I just wanted to drop a quick note to say how much I like your blog, form here in Massachusetts. Whenever I fire-up my news reader and see that your rss file has been updated, it makes me happy knowing that I will be reading about your adventures and exploits. And the photos are super too!

Posted by: Bill at January 20, 2004 12:40 PM

Do you wanna link our

www.geology.ohio-state.edu/TAMDEF web page and point to the deployment pictures?

Mike

Posted by: Mike at January 20, 2004 2:42 PM

As always, great pictures and terrifc narrative! Thanks again for sharing with us!

Posted by: Annmarie at January 22, 2004 7:21 AM

Beth: i read in the newspaper today that the Spirit rover over there on Mars is analyzing rocks from the Mars surface. Olivine is apparently a component of those rocks.

It's all coming together now.

Posted by: billmill at January 22, 2004 7:44 AM

the guys loved your picts. the green rocks looks like stuff in our frig.. time to get a rookie to clean it. love the picts. and the adventures. keep them comeing. we all love to read them.


rob and the guys at "Lucky's 13" fire station

Posted by: Lucky 13 -firhouse (rob0 at January 25, 2004 11:29 AM

This blog is wonderful! It is very interesting to read and fantastic photos too!

Posted by: bk at January 28, 2004 1:52 AM

Very cool photos. It's been very interesting to read about your adventure.

Posted by: mz. em at January 31, 2004 5:07 AM

Please contact me re pix.... Very Imp.

(Dr) Bernie Gunn.

Posted by: Dr B Gunn at February 27, 2004 2:29 PM