Showing posts with label Kerguelen. Show all posts
Showing posts with label Kerguelen. Show all posts

Saturday, August 18, 2007

Sub-Antarctic 2006 : Photo Album

In March - April 2006, I went on a summer campaign to the Sub-Antarctic islands of Kerguelen, Crozet, St Paul and Amsterdam in the southern Indian Ocean. The following is a selection of the photo-album I made during the campaign.

This is an entirely personal view of the OP2006-1 which took me to the French Austral and Antarctic Territories. Many thanks to all those who made this trip possible, and to the travelling companions who made it so pleasant. Pascal, Michel, Lionel, Henri, Nicolas: you will find here a few of your photos to help me tell this story. Alessia

Marion Dufresne II

For a large part of the trip we were on board the Marion Dufresne II, a multi-functional scientific ship operated by the TAAF and by the Paul Emil Victor Institute (IPEV). The Marion was our floating home. A home with a view on the immensity of the ocean, which draws the eye to the distant horizon, and which is populated by strange creatures: black eyebrow albatross, flying fish, killer whales.




Crozet

Our first landfall was Possession Island, a land of wind and rain, where the vegetation clings close to the ground. The sky is the reign of the great albatross and the giant petrel; the waters are the reign of the royal penguin and the killer whale. I spent my only free afternoon at the royal penguin colony, surrounded by the stinking cacophony of many thousands of these strange but elegant creatures.





Kerguelen

An island of magnificent landscapes, Morbihan gulf, Ratmanhoff bay, Mount Ross, Greenland bay, Black Eyebrow canyon, Drumlins plateau and Studer valley, where I went hiking for two days. An island where the weather changes rapidly, where the games of light and shadow are continuous, and where the wind is king. The wind of Kerguelen knows no obstacles, it drives the rain, it stops the waterfalls, it grabs the waters of the rivers and the tiny humans that would cross them making them both fly, it is indisputably the absolute master of this land.







St Paul

A magnificent volcanic crater, a nature preservation, home to jumping penguins and fur seals. No penguins were visible because of the time of year, but there were many seals on the path up to the summit. The IPEV team: Roland, Henri and Nico.





Amsterdam

This is easily the most gentle island, with its moderate temperatures, its long grasses and its trees. One side of the island is a gentle slope marked by many small volcanic craters, with the Amsterdam gardens, the Phylica wood, BMG, Antonelli, Benedict point, the Virgin. The other side is dominated by a magnificent cliff, which has to be rappelled in order to arrive at Entrecasteaux. For fauna, watch out for the fur seals: they are everywhere!





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Keep up to date with the latest developments at http://sismordia.blogspot.com

Thursday, August 16, 2007

Featured earthquakes #2 : Kerguelen


As promised in this post a while back, here is a short post about the M5.2 event that occurred on the island of Kerguelen at the end of July.

Kerguelen is a volcanic island in the Southern Pacific ocean. Its "known" seismicity is very low. However, as it is in a region with very few seismic stations, "low seismicity" may also mean low-level seismicity that is too small to be recorded on a sensible number of stations.

The M5.2 Kerguelen Island event was recorded on many seismographs of the global network, and is therefore reasonably well located. One of the stations that recorded the event is PAF (Port aux Francais) which is located on Kerguelen itself.

The PAF station also located several aftershocks. You can see the records for these aftershocks in the following images. The seismograms show vertical component of motion, high-pass filtered at 2 seconds.

The first figure shows the main-shock record in red, followed by the aftershocks recorded on the first day in black.

The second shows the main-shock again, followed by the aftershocks recorded on days 2 to 10 after the event.
Note how similar the aftershocks are to each other and to the main-shock.

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Keep up to date with the latest developments at http://sismordia.blogspot.com