Title
Interevent-time distribution and aftershock frequency in non-stationary induced seismicity
Author
Post, R.A.J.
Michels, M.A.J.
Ampuero, J.P.
Candela, T.
Fokker, P.A.
van Wees, J.D.
van der Hofstad, R.W.
van den Heuvel, E.R.
Publication year
2021
Abstract
The initial footprint of an earthquake can be extended considerably by triggering of clustered aftershocks. Such earthquake–earthquake interactions have been studied extensively for data-rich, stationary natural seismicity. Induced seismicity, however, is intrinsically inhomogeneous in time and space and may have a limited catalog of events; this may hamper the distinction between human-induced background events and triggered aftershocks. Here we introduce a novel Gamma Accelerated-Failure-Time model for efficiently analyzing interevent-time distributions in such cases. It addresses the spatiotemporal variation and quantifies, per event, the probability of each event to have been triggered. Distentangling the obscuring aftershocks from the background events is a crucial step to better understand the causal relationship between operational parameters and non-stationary induced seismicity. Applied to the Groningen gas field in the North of the Netherlands, our model elucidates geological and operational drivers of seismicity and has been used to test for aftershock triggering. We find that the hazard rate in Groningen is indeed enhanced after each event and conclude that aftershock triggering cannot be ignored. In particular we find that the non-stationary interevent-time distribution is well described by our Gamma model. This model suggests that 27.0(± 8.5)% of the recorded events in the Groningen field can be attributed to triggering.
Subject
gas field
human
Netherlands
probability
To reference this document use:
http://resolver.tudelft.nl/uuid:d942db95-df36-43a8-b125-f4a81e53ed36
DOI
https://doi.org/10.1038/s41598-021-82803-2
TNO identifier
953363
Publisher
Nature
ISSN
2045-2322
Source
Scientific Reports, 11 (11)
Document type
article