 |
 |
 |
LIVING ON A CRUSTAL FLEXURE
THE STORY TOLD BY HAWAII'S
SUBMARINE TERRACES
THE STORY TOLD BY HAWAII'S
SUBMARINE TERRACES
|
|||
| July 11, 2010 |
|||
|
|||
LIVING ON A CRUSTAL FLEXURE THE STORY TOLD BY HAWAII'S SUBMARINE TERRACES |
| I
think it was in 1958 that there was an International Geophysical Year
during which measurements were made of the sinking (or subsidence) of
the Hawaiian Islands into the underlying crust of the Earth. This was
due to "volcanic loading," the geophysicists asserted. Scientists have since then been refining and integrating reams of sea-floor depth data to chart the tilting of submarine terraces. These data can be interpreted to get an idea of how the zone of greatest subsidence has been moving about beneath the islands. Such movements are also related to a flexure of the upper crust in the general area. A comprehensive study of terrace tiltings, like the one reported below, allows a long-sought explanation of what has been occurring beneath the islands over geologic time, with respect to the direction of the maximum subsidence zone and an associated upward bulge in the lithosphere. (The lithosphere is the rigid crust and uppermost mantle of the Earth. Its thickness is on the order of 60 miles, and it is stronger than the underlying asthenosphere.) |
More follows, however... |
|
|
|
| Subscribers: |  |