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Atmospheric Precipitation and Anomalous Upper Mantle in Relation to Intraplate Seismicity in Norway
Author(s) -
Maystrenko Yuriy Petrovich,
Brönner Marco,
Olesen Odleiv,
Saloranta Tuomo Mikael,
Slagstad Trond
Publication year - 2020
Publication title -
tectonics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.465
H-Index - 134
eISSN - 1944-9194
pISSN - 0278-7407
DOI - 10.1029/2020tc006070
Subject(s) - induced seismicity , geology , intraplate earthquake , seismology , crust , mantle (geology) , upper crust , geophysics , tectonics
Two enigmatic regions of high intraplate seismicity in Norway (Western Norway and the Nordland area) show a temporal correlation between the number of earthquakes within the upper crystalline crust and intensity of rain and snowmelt at the Earth's surface. This correlation is obvious in the Nordland area where detailed and reliable data on seismicity are available, whereas the correlation is weaker in Western Norway where detailed data on seismicity are missing. Moreover, these discrete zones of high seismic activity coincide spatially with prominent, low‐velocity, and, most likely, thermally anomalous zones in the upper mantle. We propose that in addition to other causes, the high seismicity may be controlled by the anomalous upper mantle, along with topographically induced gravitational potential energy and crustal density variations. Precipitation‐induced, seasonal increases in pore‐fluid pressure within the fractured crystalline bedrock and changes in water loads may modulate the tectonically controlled seismicity.