Please use this identifier to cite or link to this item: http://hdl.handle.net/2122/5251
AuthorsTondi, R.* 
Achauer, U.* 
Landes, M.* 
Davi', R.* 
Besutiu, L.* 
TitleUnveiling seismic and density structure beneath the Vrancea seismogenic zone, Romania
Issue Date12-Nov-2009
Series/Report no./114 (2009)
DOI10.1029/2008JB005992
URIhttp://hdl.handle.net/2122/5251
Keywordsjoint inversion
density
Subject Classification04. Solid Earth::04.01. Earth Interior::04.01.02. Geological and geophysical evidences of deep processes 
AbstractThe Vrancea seismogenic zone in Romania exhibits an intense intermediate-depth seismicity, confined to a relatively small, roughly cylindrical and elongated region, whose origin is still under debate. Our three-dimensional P and S wave velocity and density images put additional physical constraints on the existing tectonic models to a depth of 200 km. The results appear to substantiate a combination of lithospheric delamination and oceanic subduction. For our analysis, we apply the tomographic inversion method of sequential integrated inversion (SII) to P and S first arrivals from active source data collected during the VRANCEA99 and VRANCEA2001 seismic refraction experiments, local earthquake data collected during the Carpathian Arc Lithosphere X-Tomography (CALIXTO) experiment and recent gravity measurements of the studied area. The reconstructed models, which explain both travel times and gravity data, show a subducting slab which exhibits fast Vp, fast Vs, high density, and a low Vp/Vs ratio consistent with the cold downgoing plate. We associate intermediate-depth seismicity with the observed sharp lateral Vp/Vs variations presumably generated by contact between the dense and cold slab and the lithospheric mantle in the shallower part or the asthenosphere in the deeper part. This contrast is particularly evident between 100 and 150 km depth, where the maximum historical seismic energy release is concentrated. Our results indicate the diagnostic power of a combined interpretation of 3-D Vp, Vs, Vp/Vs, and density models.
DescriptionAn edited version of this paper was published by AGU. Copyright (2009) American Geophysical Union
Appears in Collections:Papers Published / Papers in press

Files in This Item:
File Description SizeFormat 
2008JB005992.pdf"Article in proof"5.58 MBAdobe PDFView/Open    Request a copy
Show full item record

Page view(s)

110
checked on May 24, 2017

Download(s)

31
checked on May 24, 2017

Google ScholarTM

Check

Altmetric