Artículo de revista
Earthquake magnitude calculation without saturation from the scaling of peak ground displacement
Fecha
2015Registro en:
Geophysical Research Letters Volumen: 42 Número: 13 Jul 16 2015
DOI: 10.1002/2015GL064278
Autor
Melgar, Diego
Crowell, Brendan W.
Geng, Jianghui
Allen, Richard M.
Bock, Yehuda
Riquelme, Sebastián
Hill, Emma M.
Protti, Marino
Ganas, Athanassios
Institución
Resumen
GPS instruments are noninertial and directly measure displacements with respect to a
global reference frame, while inertial sensors are affected by systematic offsets—primarily tilting—that
adversely impact integration to displacement. We study the magnitude scaling properties of peak ground
displacement (PGD) from high-rate GPS networks at near-source to regional distances (~10–1000 km),
from earthquakes between Mw6 and 9. We conclude that real-time GPS seismic waveforms can be used to
rapidly determine magnitude, typically within the first minute of rupture initiation and in many cases
before the rupture is complete. While slower than earthquake early warning methods that rely on the
first few seconds of P wave arrival, our approach does not suffer from the saturation effects experienced
with seismic sensors at large magnitudes. Rapid magnitude estimation is useful for generating rapid
earthquake source models, tsunami prediction, and ground motion studies that require accurate information
on long-period displacements.