کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4693005 1636833 2011 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Seismicity and velocity structures along the south-Alpine thrust front of the Venetian Alps (NE-Italy)
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Seismicity and velocity structures along the south-Alpine thrust front of the Venetian Alps (NE-Italy)
چکیده انگلیسی

In this paper we show the seismicity and velocity structure of a segment of the Alpine retro-belt front along the continental collision margin of the Venetian Alps (NE Italy). Our goal is to gain insight on the buried structures and deep fault geometry in a “silent” area, i.e., an area with poor instrumental seismicity but high potential for future earthquakes, as indicated by historical earthquakes (1695 Me = 6.7 Asolo and 1936 Ms = 5.8 Bosco del Cansiglio). Local earthquakes recorded by a dense temporary seismic network are used to compute 3-D Vp and Vp/Vs tomographic images, yielding well resolved images of the upper crust underneath the south-Alpine front. We show the presence of two main distinct high Vp S-verging thrust units, the innermost coincides with the piedmont hill and the outermost is buried under a thick pile of sediments in the Po plain.Background seismicity and Vp/Vs anomalies, interpreted as cracked fluid-filled volumes, suggest that the NE portion of the outermost blind thrust and its oblique/lateral ramps may be a zone of high fluid pressure prone to future earthquakes.Three-dimensional focal mechanisms show compressive and transpressive solutions, in agreement with the tectonic setting, stress field maps and geodetic observations. The bulk of the microseismicity is clustered in two different areas, both in correspondence of inherited lateral ramps of the thrust system. Tomographic images highlight the influence of the paleogeographic setting in the tectonic style and seismic activity of the region.


► We show the results of a microseismic study in a highly potential seismic area.
► Focal mechanisms are in agreement with the tectonic setting and the geodesic data.
► The bulk of seismicity is located in correspondence of the inherited lateral ramps.
► Paleogeographic setting influences the tectonic style and the seismic activity.
► NE of Montello thrust may be a high fluid pressure zone prone to future earthquakes.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Tectonophysics - Volume 513, Issues 1–4, 5 December 2011, Pages 37–48
نویسندگان
, , , ,