Short Period Surface Wave Dispersion Across the Mediterranean Region: Improvements Using Regional Seismic Networks
Abstract
We have begun to apply ambient noise surface wave tomography to broad-band seismic data obtained in Europe, North Africa, the Middle East, and Central Asia. The goal is to improve the calibration of surface wave propagation in aseismic area. Ambient noise tomography (ANT) generates surface wave dispersion maps to periods as short as 6 across large areas and, therefore, provides new, high resolution constraints on crustal structures homogeneously over extended regions. Current work concentrates on the application of ANT in Europe where station coverage is highest, which allows improvements in the method to be made rapidly and transported elsewhere later. In earlier work, we applied ambient noise tomography across Europe to one year of data from approximately 125 stations composing the Virtual European Seismic Network (VEBSN) (available from the ORFEUS Data Center) to produce Rayleigh wave group velocity maps from an 8-40 sec period. Current work builds on these results by using longer time series (to improve signal quality and provide measurement uncertainties) and assimilating data from temporary or emerging regional networks in the Mediterranean region to generate Rayleigh wave phase and group speed maps across Europe with better resolution and reliability. The study concentrates on improvements in three focus areas where regional array data are available: (1) the western Mediterranean, particularly the Iberian Peninsula, (2) the central Mediterranean, notably Italy and Switzerland, and (3) the eastern Mediterranean, including Israel, Syria, and Turkey. The western Mediterranean results are based on the Spanish National Network data, which provides much tighter constraints on the crustal structures of the Iberian Peninsula. In the Central Mediterranean, the RETREAT and CAT-SCAN Program for the Array Seismic Studies of the Continental Lithosphere (PASSCAL) experiments yield data that improve resolution in this area considerably.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2007
- Accession Number
- ADA519914
Entities
People
- Antonio Villasenor
- Arthur Lerner-lam
- Michael E. Pasyanos
- Michael H. Ritzwoller
- Nadezda V. Kraeva
- Rachelle M. Richmond
- Rami Hofstetter
- Vadim Levin
- Vladimir I. Pinsky
- Yingjie Yang
Organizations
- University of Colorado Boulder