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| Titel |
P-wave tomographic structure of NE Tibet |
| VerfasserIn |
Ceri Nunn, Frederik Tilmann, Keith Priestley, Steven Roecker, Ross Heyburn |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250052790
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| Zusammenfassung |
| We invert a data set of more than 26,000 teleseismic P-wave arrival times to determine the
variation in compressional wave structure beneath NE Tibet. The seismograms from which
the arrival times were read were recorded from 572 events at 80 stations from the ASCENT
and INDEPTH IV experiments from 2007-2009. The motivation for the experiments was
to extend earlier seismic surveys to the edge of the plateau, and consider an area
which contains the Kunlun Fault, and the Jinsha and Bangong-Nujiang sutures. The
experiments are intended to resolve issues such as how deep the fault zones extend, the
variation in Moho depth across the region, and consider the viability of the crustal flow
hypothesis.
The resulting tomographic models show a number of large scale features. There is a slow
anomaly extending to 400km depth across the Kunlun Qaidam and Songpan Ganzi terranes,
from approximately 91°E to 95°E. There is an extensive fast region across the Qiantang
from 31°N to 34°N and 90°E to 94°E, which also appears to persist to 400km depth.
There is a deep, fast anomaly across the Qaidam Basin, with a sharp transition to slower
material to the south. The resolution tests suggest that resolution of features tens of
kilometres wide is possible, but with significant smearing (particularly in the vertical
direction). |
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