Spatiotemporal Variations of the Frequency–Magnitude Distribution in the 2019 <i>M</i><sub>w</sub> 7.1 Ridgecrest, California, Earthquake Sequence

Significant seismic activity has been witnessed in the area of Ridgecrest (Southern California) over the past 40 years, with the largest being the <i>M</i><sub>w</sub> 5.8 event on 20 September 1995. In July 2019, a strong earthquake of <i>M</i><sub>w</su...

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Main Authors: Eirini Sardeli, Georgios Michas, Kyriaki Pavlou, Filippos Vallianatos
Format: Article
Language:English
Published: MDPI AG 2023-12-01
Series:Entropy
Subjects:
Online Access:https://www.mdpi.com/1099-4300/25/12/1612
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author Eirini Sardeli
Georgios Michas
Kyriaki Pavlou
Filippos Vallianatos
author_facet Eirini Sardeli
Georgios Michas
Kyriaki Pavlou
Filippos Vallianatos
author_sort Eirini Sardeli
collection DOAJ
description Significant seismic activity has been witnessed in the area of Ridgecrest (Southern California) over the past 40 years, with the largest being the <i>M</i><sub>w</sub> 5.8 event on 20 September 1995. In July 2019, a strong earthquake of <i>M</i><sub>w</sub> 7.1, preceded by a <i>M</i><sub>w</sub> 6.4 foreshock, impacted Ridgecrest. The mainshock triggered thousands of aftershocks that were thoroughly documented along the activated faults. In this study, we analyzed the spatiotemporal variations of the frequency–magnitude distribution in the area of Ridgecrest using the fragment–asperity model derived within the framework of non-extensive statistical physics (NESP), which is well-suited for investigating complex dynamic systems with scale-invariant properties, multi-fractality, and long-range interactions. Analysis was performed for the entire duration, as well as within various time windows during 1981–2022, in order to estimate the <i>q<sub>M</sub></i> parameter and to investigate how these variations are related to the dynamic evolution of seismic activity. In addition, we analyzed the spatiotemporal <i>q<sub>M</sub></i> value distributions along the activated fault zone during 1981–2019 and during each month after the occurrence of the <i>M</i><sub>w</sub> 7.1 Ridgecrest earthquake. The results indicate a significant increase in the <i>q<sub>M</sub></i> parameter when large-magnitude earthquakes occur, suggesting the system’s transition in an out-of-equilibrium phase and its preparation for seismic energy release.
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spelling doaj.art-8dcab608fc454683a3a3e1d9cb1d55202023-12-22T14:07:22ZengMDPI AGEntropy1099-43002023-12-012512161210.3390/e25121612Spatiotemporal Variations of the Frequency–Magnitude Distribution in the 2019 <i>M</i><sub>w</sub> 7.1 Ridgecrest, California, Earthquake SequenceEirini Sardeli0Georgios Michas1Kyriaki Pavlou2Filippos Vallianatos3Section of Geophysics-Geothermics, Department of Geology and Geoenvironment, National and Kapodistrian University of Athens, 15772 Athens, GreeceSection of Geophysics-Geothermics, Department of Geology and Geoenvironment, National and Kapodistrian University of Athens, 15772 Athens, GreeceSection of Geophysics-Geothermics, Department of Geology and Geoenvironment, National and Kapodistrian University of Athens, 15772 Athens, GreeceSection of Geophysics-Geothermics, Department of Geology and Geoenvironment, National and Kapodistrian University of Athens, 15772 Athens, GreeceSignificant seismic activity has been witnessed in the area of Ridgecrest (Southern California) over the past 40 years, with the largest being the <i>M</i><sub>w</sub> 5.8 event on 20 September 1995. In July 2019, a strong earthquake of <i>M</i><sub>w</sub> 7.1, preceded by a <i>M</i><sub>w</sub> 6.4 foreshock, impacted Ridgecrest. The mainshock triggered thousands of aftershocks that were thoroughly documented along the activated faults. In this study, we analyzed the spatiotemporal variations of the frequency–magnitude distribution in the area of Ridgecrest using the fragment–asperity model derived within the framework of non-extensive statistical physics (NESP), which is well-suited for investigating complex dynamic systems with scale-invariant properties, multi-fractality, and long-range interactions. Analysis was performed for the entire duration, as well as within various time windows during 1981–2022, in order to estimate the <i>q<sub>M</sub></i> parameter and to investigate how these variations are related to the dynamic evolution of seismic activity. In addition, we analyzed the spatiotemporal <i>q<sub>M</sub></i> value distributions along the activated fault zone during 1981–2019 and during each month after the occurrence of the <i>M</i><sub>w</sub> 7.1 Ridgecrest earthquake. The results indicate a significant increase in the <i>q<sub>M</sub></i> parameter when large-magnitude earthquakes occur, suggesting the system’s transition in an out-of-equilibrium phase and its preparation for seismic energy release.https://www.mdpi.com/1099-4300/25/12/1612Ridgecrestearthquake sequencefrequency–magnitude distributionfragment–asperity modelTsallis entropynon-extensive statistical physics
spellingShingle Eirini Sardeli
Georgios Michas
Kyriaki Pavlou
Filippos Vallianatos
Spatiotemporal Variations of the Frequency–Magnitude Distribution in the 2019 <i>M</i><sub>w</sub> 7.1 Ridgecrest, California, Earthquake Sequence
Entropy
Ridgecrest
earthquake sequence
frequency–magnitude distribution
fragment–asperity model
Tsallis entropy
non-extensive statistical physics
title Spatiotemporal Variations of the Frequency–Magnitude Distribution in the 2019 <i>M</i><sub>w</sub> 7.1 Ridgecrest, California, Earthquake Sequence
title_full Spatiotemporal Variations of the Frequency–Magnitude Distribution in the 2019 <i>M</i><sub>w</sub> 7.1 Ridgecrest, California, Earthquake Sequence
title_fullStr Spatiotemporal Variations of the Frequency–Magnitude Distribution in the 2019 <i>M</i><sub>w</sub> 7.1 Ridgecrest, California, Earthquake Sequence
title_full_unstemmed Spatiotemporal Variations of the Frequency–Magnitude Distribution in the 2019 <i>M</i><sub>w</sub> 7.1 Ridgecrest, California, Earthquake Sequence
title_short Spatiotemporal Variations of the Frequency–Magnitude Distribution in the 2019 <i>M</i><sub>w</sub> 7.1 Ridgecrest, California, Earthquake Sequence
title_sort spatiotemporal variations of the frequency magnitude distribution in the 2019 i m i sub w sub 7 1 ridgecrest california earthquake sequence
topic Ridgecrest
earthquake sequence
frequency–magnitude distribution
fragment–asperity model
Tsallis entropy
non-extensive statistical physics
url https://www.mdpi.com/1099-4300/25/12/1612
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