• Sorted by Date • Sorted by Last Name of First Author •
Colledge, Martin, Chanard, Kristel, Duverger, Clara, Schubnel, Alexandre, Adhikari, Lok Bijaya, and Bollinger, Laurent, 2025. Annual variations in Nepalese seismicity: b-values and seismicity rates. Geophysical Journal International, .
• from the NASA Astrophysics Data System • by the DOI System •
@ARTICLE{2025GeoJI.tmp..271C, author = {{Colledge}, Martin and {Chanard}, Kristel and {Duverger}, Clara and {Schubnel}, Alexandre and {Adhikari}, Lok Bijaya and {Bollinger}, Laurent}, title = "{Annual variations in Nepalese seismicity: b-values and seismicity rates}", journal = {Geophysical Journal International}, year = 2025, month = jul, abstract = "{Seasonal variations in Nepalese seismicity have been reported with varying degrees of confidence. We re-investigate these claims by analysing 20 years of Nepalese seismicity before the 2015 Gorkha earthquake, as detected by the Nepalese national network, and focusing on earthquakes located along the eastern and central sections of the Nepalese Main Himalayan Thrust. Using several declustering techniques, we find no statistically robust evidence of seasonal seismicity in the studied record, regardless of magnitude threshold above completeness. This suggests that previously reported seasonality may be restricted to the western section of the Nepalese orogeny, may be an artefact, or may indicate that nucleation times of earthquakes are longer than the year. We also investigate potential annual variations in the Gutenberg-Richter b-value, given its recent observed modulation by transient stressing. Additionally, we use large-scale mass redistribution estimated from the monthly gravity field retrieved from the Gravity Recovery And Climate Experiment and Follow-On (GRACE/-FO) missions, to resolve stress variations at depth induced by transient surface loads. We find that the mean annual b-value peaks when seasonal Coulomb stress rates reach their minimum value at the height of the summer rainy season. When considering the combined effect of tectonic and seasonal loading, this corresponds to a recurring period of stress reversal, when Coulomb stress momentarily decreases. This suggests that periodic clamping of the Main Himalayan Thrust reduces the likelihood of earthquakes growing to larger magnitudes in accordance with hierarchical rupture models. The susceptibility of b-value to stress variations of roughly 0.1 points.kPa$^{-1}$ is consistent with recent estimates of b-value sensitivity to transient loading, although it remains high when compared to the stress-dependency associated with both static differential stress, and with long-term evolution during the seismic cycle. This discrepancy points to the large impact of stress transients on the dynamics of seismic rupture.}", doi = {10.1093/gji/ggaf259}, adsurl = {https://ui.adsabs.harvard.edu/abs/2025GeoJI.tmp..271C}, adsnote = {Provided by the SAO/NASA Astrophysics Data System} }
Generated by
bib2html_grace.pl
(written by Patrick Riley
modified for this page by Volker Klemann) on
Thu Aug 14, 2025 17:55:12
GRACE-FO
Thu Aug 14, F. Flechtner