Articles | Volume 15, issue 12
Nat. Hazards Earth Syst. Sci., 15, 2697–2701, 2015
Nat. Hazards Earth Syst. Sci., 15, 2697–2701, 2015

Comment/reply 18 Dec 2015

Comment/reply | 18 Dec 2015

Comment on "Ultra low frequency (ULF) electromagnetic anomalies associated with large earthquakes in Java Island, Indonesia by using wavelet transform and detrended fluctuation analysis" by Febriani et al. (2014)

F. Masci1 and J. N. Thomas2,3,4 F. Masci and J. N. Thomas
  • 1Istituto Nazionale di Geofisica e Vulcanologia, L'Aquila, Italy
  • 2NorthWest Research Associates, Redmond, Washington, USA
  • 3Department of Electrical and Computer Engineering, DigiPen Institute of Technology, Redmond, Washington, USA
  • 4Department of Earth and Space Sciences, University of Washington, Seattle, Washington, USA

Abstract. We examine the recent report of Febriani et al. (2014) in which the authors show changes in ULF magnetic field data prior to the M7.5 Tasikmalaya earthquake that occurred south of Java, Indonesia, on 2 September 2009. Febriani et al. (2014) state that the magnetic changes they found may be related to the impending earthquake. We do not agree that the pre-earthquake magnetic changes shown in Febriani et al. (2014) are seismogenic. These magnetic changes, indeed, are too closely related to global geomagnetic disturbances to be regarded as being of seismic origin.

Short summary
Reports of possible earthquake precursors have social responsibility. They motivate the idea that earthquakes may be predicted in the future. Thus, these papers should be convincing about the seismogenic origin of the reported precursors. We have reviewed Febriani et al. (2014). We have shown that the pre-earthquake magnetic changes they reported are not seismogenic but global-scale variations in the geomagnetic field in response to Sun–Earth interactions.
Final-revised paper