 |
| Titel |
Update on CRUST1.0 - A 1-degree Global Model of Earth's Crust |
| VerfasserIn |
Gabi Laske, Guy Masters, Zhitu Ma, Mike Pasyanos |
| Konferenz |
EGU General Assembly 2013
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250074017
|
|
|
|
|
|
| Zusammenfassung |
| Our new 1-by-1 degree global crustal model, CRUST1.0, was introduced last year and serves
as starting model in a comprehensive effort to compile a global model of Earth’s crust and
lithosphere, LITHO1.0 (Pasyanos et al., 2012). The Moho depth in CRUST1.0 is based on
1-degree averages of a recently updated database of crustal thickness data from active source
seismic studies as well as from receiver function studies. In areas where such constraints are
still missing, for example in Antarctica, crustal thicknesses are estimated using gravity
constraints.
The compilation of the new crustal model initially followed the philosophy of the widely
used crustal model CRUST2.0 (Bassin et al., 2000; http://igppweb.ucsd.edu/~gabi/crust2.html)
to assign elastic properties in the crystalline crust according to basement age or
tectonic setting (loosely following an updated map by Artemieva and Mooney (2001;
http://www.lithosphere.info). For cells with no local seismic or gravity constraints, statistical
averages of crustal properties, including crustal thickness, were extrapolated. However, in
places with constraints the depth to basement and mantle are given explicitly and
no longer assigned by crustal type. This allows for much smaller errors in both.
In each 1-degree cell, boundary depth, compressional and shear velocity as well as
density is given for 8 layers: water, ice, 3 sediment layers and upper, middle and lower
crystalline crust. Topography, bathymetry and ice cover are taken from ETOPO1.
The sediment cover is based on our sediment model (Laske and Masters, 1997;
http://igppweb.ucsd.edu/~sediment.html), with some near-coastal updates. In an initial step
toward LITHO1.0, the model is then validated against new global surface wave disperison
maps and adjusted in areas of extreme misfit. This poster presents the next validation step:
compare the new Moho depths with in-situ active source and receiver function
results. We also present comparisons with CRUST2.0. CRUST1.0 is available for
download.
References:
Pasyanos, M.E., Masters, G., Laske, G. and Ma, Z., LITHO1.0 – An Updated Crust and
Lithospheric Model of the Earth Developed Using Multiple Data Constraints, Abstract
T11D-09 presented at 2012 Fall Meeting, AGU, San Francisco, Calif., 3-7 Dec,
2012.
Artemieva, I.M. and Mooney, W.D., Thermal thickness and evolution of Precambrian
lithosphere: A global study, J. Geophys. Res., 106, 16,387-16,414, 2001.
Bassin, C., Laske, G. and Masters, G., The Current Limits of Resolution for Surface Wave
Tomography in North America, EOS Trans AGU, 81, F897, 2000.
Laske, G. and Masters, G., A Global Digital Map of Sediment Thickness, EOS Trans.
AGU, 78, F483, 1997.
URL: http://igppweb.ucsd.edu/~gabi/crust1.html |
|
|
|
|
|
|