Pure and Applied Geophysics

, Volume 173, Issue 4, pp 1021–1027 | Cite as

Low-Frequency Centroid Moment Tensor Inversion of the 2015 Illapel Earthquake from Superconducting-Gravimeter Data

  • Eliška Zábranová
  • Ctirad Matyska
Part of the following topical collections:
  1. Illapel, Chile, Earthquake on September 16th, 2015


After the 2015 Illapel earthquake the radial and spheroidal modes up to 1 mHz were registered by the network of superconducting gravimeters. These data provide unique opportunity to obtain ultralow-frequency estimates of several centroid moment tensor components. We employ the superconducting-gravimeter records of 60-h lengths and perform the joint inversion for \(M_{rr}\), \((M_{\vartheta \vartheta }-M_{\varphi \varphi })/2\) and \(M_{\vartheta \varphi }\) centroid moment tensor components from spheroidal modes up to 1 mHz. The \(M_{rr}\) component is also obtained from independent inversion of the radial modes \(_0S_0\) and \(_1S_0\). Our results are consistent with the published solutions obtained from higher frequency data, suggesting thus negligible slow afterslip phenomenon.


2015 Illapel earthquake superconducting-gravimeter data normal modes CMT inversion 



We thank F. Gallovič for discussion and an anonymous reviewer for detailed and helpful comments. We highly appreciate the help of V. Pálinkáš with data accessibility. The data were downloaded from the IGETS webpage: This research was supported by the Grant Agency of the Czech Republic (GAČR) under the project No. 14-04372S and the project CzechGeo/EPOS.


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© Springer International Publishing 2016

Authors and Affiliations

  1. 1.Department of Geophysics, Faculty of Mathematics and PhysicsCharles University in PraguePragueCzech Republic

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