LITHO1.0: An Updated Crust and Lithosphere Model of the Earth
Abstract
We are developing LITHO1.0: an updated crust and lithosphere model of the Earth. The overall plan is to take the popular CRUST2.0 model--a global model of crustal structure with a relatively poor representation of the uppermost mantle--and improve its nominal resolution to 1 degree and extend the model to include lithospheric structure. The new model, LITHO 1.0, will be constrained by many different datasets, including extremely large new datasets of relatively short-period group velocity data measured with a new technique which are sensitive to lid properties as well as crustal thickness and average crustal properties. Other datasets include (but are not limited to) compilations of receiver function constraints and active source studies. This year, most progress was made on surface-wave measurements. We use a cluster analysis technique to measure surface-wave group velocity from 10mHz to 40mHz . We use all the LH data from the Data Management Center (DMC) of Incorporated Research Institutions for Seismology (IRIS) between 1976 and 2007. The Rayleigh wave group velocity dataset is complete. The current dataset has about 330000 measurements for each of 10 mHz and 20mHz, 210000 for 30mHz, and 45000 for 40mHz. We also include some BH data from Program for Array Seismic Studies of the Continental Lithosphere (PASSCAL) in the southern hemisphere and the Portable Observatories for Lithospheric Analysis and Research Investigating Seismicity (POLARIS) network to increase ray coverage. Initial inversions of the datasets show features consistent with geophysical observation. Some artifacts are found in the ocean regions at high frequencies due to limited ray coverage. A solution we are currently pursuing is to implement an a priori group velocity model based on the age of oceanic lithosphere, which will be used to constrain the inversions where necessary.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2010
- Accession Number
- ADA530686
Entities
People
- Gabi Laske
- Mike Pasyanos
- T. G. Masters
- Zhitu Ma
Organizations
- University of California, San Diego