R/V Marcus Langseth
Marine Geophysics
| In the summer of 2008, researchers
and students at UTIG will be sailing on the R/V Marcus Langseth to
acquire marine geophysical data across the Yakutat block. The funded
survey includes two reflection-refraction profiles, one down the
long-axis of the exposed block and one crossing it and the proximal
Pacific plate, and two grids of reflection data over fault zones that
may be regionally significant. The seismic source will be received on
the Langseth's 8 km digital, solid streamer for the reflection work and
on a series of Ocean
Bottom Seismometers (OBS) offshore and Texan seismometers onshore for
the refraction work. The goals of the experiment are to: 1) Determine
the type of crust that makes up the Yakutat block to test competing
models of plateau subduction versus continental-oceanic accretion, 2)
Examine the connections at depth between well-known surface structures
such as the Pamplona Zone, the Kayak Island fault zone, and their
onshore extensions and the deeper architecture of the collision, and 3)
To investigate the role of glacial erosion and
sediment transport in influencing mountain building. In preparation for
this work researcher Sean Gulick, student Lindsay Lowe, and their
colleagues are analyzing the deformation recorded on previously acquired
industry, USGS, and high-resolution academic seismic data sets. The
STEEP project and allied investigations are providing the framework for
proposed Integrated Ocean Drilling Program (IODP) expeditions to study
tectonic-climate interactions in the Gulf of Alaska.
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