Seismic source characteristics of the intermediate-depth and intraslab 2019 northern Peru earthquake (Mw 8.0)

• Published in: Journal of seismology Vol. 25; no. 3; pp. 863 - 874
• Main Authors: Jiménez, César, Luna, Nestor, Moreno, Nick, J., Miguel Saavedra
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.06.2021; Springer Nature B.V
• Subjects: Deformation; Depth; Dimensions; Directivity; Earth and Environmental Science; Earth Sciences; Earthquakes; Geophysics/Geodesy; Geotechnical Engineering & Applied Earth Sciences; Hydrogeology; Original Article; Plates; Propagation velocity; Rupture; Rupturing; Seismic activity; Seismic energy; Seismology; Slip; Spectral analysis; Spectrum analysis; Structural Geology; Time functions; Waveforms; Peru; Slip distribution; Seismic source; Numerical simulation
• ISSN: 1383-4649; 1573-157X
• DOI: 10.1007/s10950-021-09996-x

On May 26, 2019, an unusual depth-intermediate focus earthquake, in the interior of the Nazca plate, shook the northern Peruvian jungle and caused the death of two victims. This earthquake was felt in almost all of Peru as well as Brazil, Ecuador and Colombia. The focal mechanism calculated is of the normal fault type (strike = 353 ∘ , dip = 57 ∘ , rake = − 99 ∘ ) for a focal depth of 114 km. The slip distribution was obtained through an inversion process of teleseismic waveforms. The maximum slip was 6.3 m, located around the central side of the fault plane. The moment magnitude calculated was Mw 8.0; the spectral analysis indicated a similar magnitude of Mw 8.0. The source time function indicates a multiple rupture earthquake, with the presence of several pulses of seismic energy release, with a total duration around 80 s. The rupture directivity was from the south to the north; we have assumed a propagation rupture velocity of 2.8 km/s. The modeled fault plane geometry has dimensions of 208×105 km 2 . The predicted vertical coseismic deformation field shows a pattern of mostly subsidence.