A Dynamic Rupture Source Model for Very Low-Frequency Earthquake Signal Without Detectable Nonvolcanic Tremors

Wu, Baoning; Oglesby, David D.; Ghosh, Abhijit und Li, Bo (2019): A Dynamic Rupture Source Model for Very Low-Frequency Earthquake Signal Without Detectable Nonvolcanic Tremors. In: Geophysical Research Letters, Bd. 46, Nr. 21: S. 11934-11943

Abstract

A very low-frequency earthquake is a type of seismic event that is rich in low frequencies and depleted in higher frequencies compared to regular fast local earthquakes of similar magnitude. The source process behind very low-frequency earthquakes is still poorly understood. Here we present a dynamic rupture source model for very low-frequency earthquake signal without detectable associated tremors. We show that a single asperity model with sudden stress drop followed by a rate strengthening effect damps the seismic radiation and increases event duration. We compute synthetic seismograms for our source model. The synthetic signal successfully reproduces the features of observed very low-frequency earthquakes. Moreover, the synthetic very low-frequency earthquake signal in 0.02-0.05 Hz is not accompanied by detectable tremor signals at 2-8 Hz. Our results help explain why in some cases we observe very low-frequency earthquakes without accompanying tremor.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Geowissenschaften > Department für Geo- und Umweltwissenschaften
• Themengebiete: 500 Naturwissenschaften und Mathematik > 550 Geowissenschaften, Geologie
• ISSN: 0094-8276
• Sprache: Englisch