I´m Raquel a PhD
student in the Institute of Earth Sciences Jaume Almera. Nowadays, words like fracking, gas injection or induced
seismicity are often trending topic. The development of these energy
sources requires a detailed knowledge of Earth structures.
My work is focused on using
earthquakes to know and understand the structures and properties of the earth
crust. I study the attenuation (the amplitude decay of the seismic wave with
distance) of the Lg-waves. The Lg-wave is a seismic phase that propagates
across the entire crust and whose amplitude is sensitive to changes in crustral
structure. Sharp variations in crustal thickness, scattering along tectonic
faults and fractures, and variations of the crustal properties (such as
temperature, or fluid content) are some factors that affect the Lg-wave propagation.
The Lg attenuation is calculated by means of the quality factor, Q (inversely proportional to Lg attenuation). The most striking feature observed is the contrast between low
attenuation in western
Iberia that is associated with a stable crust, and the high attenuation in the Pyrenees Range and eastern Iberia where seismic activity is relatively high and variations in
crutal structures has been observed.
Contribution of Team
Consolider-Ingenio 2010 TOPO-IBERIA (CSD2006-00041) and the MICINN Project
CGL2010-21568.
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| Lateral variation of Lg Q in the Iberian Peninsula. Lower values of Q represent zones with higher attenuation |
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