Natural Hazards Editors' Highlights

Modeling Tsunamis with Social Media

Video footage gathered from social media is used to reconstruct the timing and likely source(s) of the tsunami generated by the 2018 Palu earthquake.

Source: Geophysical Research Letters


A devastating tsunami occurred in Palu Bay on Sulawesi, Indonesia, following the 2018 Palu earthquake. This tsunami was unusually large according to conventional wisdom, because it was generated by a strike slip event. Carvajal et al. [2019] present a fascinating new approach to construct modeled tsunami waveforms using social media video footage shared by people who experienced the tsunami and recording from local CCTV cameras. These videos were analyzed to quantify the timing, amplitude, and period of the tsunami at different locations around Palu Bay.

Results show that either current rupture models of the earthquake underestimate the seafloor displacement it caused, or that non-tectonic sources were involved in generating the tsunami. This analysis also reveals significant short period tsunami waves which were not recorded by the local tide gauge because the sampling rate at the station was too large. This demonstrates that data obtained from unconventional devices can be extremely useful to better understand tsunami phenomena.

Citation: Carvajal, M., Araya‐Cornejo, C., Sepúlveda, I., Melnick, D., & Haase, J. S. [2019]. Nearly instantaneous tsunamis following the Mw 7.5 2018 Palu earthquake. Geophysical Research Letters, 46.

—Gavin P. Hayes, Editor, Geophysical Research Letters

Text © 2019. The authors. CC BY-NC-ND 3.0
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