Affiliation:
1. Ocean and Earth Science University of Southampton Southampton UK
2. The MathWorks Cambridge UK
3. Geology and Geophysics Woods Hole Oceanographic Institution Woods Hole MA USA
4. Department of Earth Sciences University of Oxford Oxford UK
Abstract
AbstractOceanic transform faults are intriguing in that they do not produce earthquakes as large as might be expected given their dimensions. We use 1‐year of local seismicity (370 events aboveMC = 2.3) recorded on an array of ocean bottom seismometers (OBSs) and geophysical data to study the seismotectonic properties of the Chain transform, located in the equatorial Mid‐Atlantic. We extend our analysis back in time by considering stronger earthquakes (MW ≥ 5.0) from global catalogs. We divide Chain into three areas (east, central, and west) based on historical event distribution, morphology, and multidimensional OBS seismicity cluster analysis. Seismic activity recorded by the OBS is the highest at the eastern area of Chain where there is a lozenge‐shaped topographic high, a negative rMBA gravity anomaly, and only a few historicalMW ≥ 5.5 events. OBS seismicity rates are lower in the western and central areas. However, these areas accommodate the majority of seismic moment release, as inferred from both OBS and historical data. Higherb‐values are significantly correlated with lower rMBA and with shallower bathymetry, potentially related to thickened crust. Our results suggest high lateral heterogeneity along Chain. Patches with moderate to low OBS seismicity rates that occasionally hostMW ≥ 6.0 earthquakes are interrupted by segments with abundant OBS activity but few historical events with 5.5 ≤ MW < 6.0. This segmentation is possibly due to variable fluid circulation and alteration, which may also change in time.
Funder
Natural Environment Research Council
European Research Council
Publisher
American Geophysical Union (AGU)
Subject
Space and Planetary Science,Earth and Planetary Sciences (miscellaneous),Geochemistry and Petrology,Geophysics
Cited by
2 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献