Tristan : Tristan Still Shakes Underground
Submitted by Tristan Times (Juanita Brock) 06.08.2004 (Article Archived on 20.08.2004)
Though quiet on the surface, there are still signs that recent seismic activity has taken place. Photo (c) James Glass Tristan Times - Rocks like these are floating all around Tristan.
TRISTAN STILL SHAKES UNDERGROUND
By J. Brock (SARTMA - TdC)
Floating rocks retreived by Tristan's fishermen
Though all may seem quiet on the surface, the latest seismic information from the Island is quite different. Many kilometres beneath the 1961 Volcano the rocks are still shaking. Indeed, there has been other seismic activity along the Atlantic Ridge, which has contributed to seismic instability in the South Atlantic.
The South Sandwich Islands have also experienced seismic activity within the same time-frame that Tristan did. However, that activity happened two weeks before on 17 July 2004 and on 30 July, with 4 and 5 readings on the Richter scale. No data has been received about the events being related, however.
At the moment, fishermen from Tristan are reporting floating rocks all around the Island. (See the photo above) This is an indicator that the activity could have been on the seabed. Tristan da Cunha is located near to the Atlantic Ridge on the African Plate and could well receive pumice from eruptions in this spreading centre. As you can see, the rocks are angular and not round. This means that they haven't travelled very far.
More information will be available as it comes in.
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