A Dynamic Model of the Frequency-Dependent Rupture Process of the 2011
, Lingsen Meng1
and Jean-Paul Ampuero1
Division of Geological and Planetary Sciences, California Institute of Technology,
Pasadena, California 91125, USA
We present a 2D dynamic rupture model that provides a physical interpretation of the key
features of the 2011 Tohoku-Oki earthquake rupture. This minimalistic model assumes
linear slip-weakening friction, the presence of deep asperities and depth-dependent initial
stresses. It reproduces the first-order observations of the along-dip rupture process during
its initial 100 s, such as large static slip and low-frequency radiation up-dip from the
hypocenter, and slow rupture punctuated by high-frequency radiation in deeper regions.
We also derive quantitative constraints on the ratio of shallow versus deep radiation from
teleseismic back-projection source imaging. This ratio is explained in our model by the
rupture of deep asperities surrounded by low stress drop regions, and by the decrease of
initial stresses towards the trench.