The 2021 Mw 5.6 Earthquake in the Guyana Shield, South America: An Intraplate Event with No Reason to Occur
Identifikátory výsledku
Kód výsledku v IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F25%3A10508374" target="_blank" >RIV/00216208:11320/25:10508374 - isvavai.cz</a>
Výsledek na webu
<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=AXSGnO62Gz" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=AXSGnO62Gz</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1785/0320250002" target="_blank" >10.1785/0320250002</a>
Alternativní jazyky
Jazyk výsledku
angličtina
Název v původním jazyce
The 2021 Mw 5.6 Earthquake in the Guyana Shield, South America: An Intraplate Event with No Reason to Occur
Popis výsledku v původním jazyce
In 31 January 2021, an Mw 5.6 earthquake occurred in the Guyana shield, causing damage to adobe houses and ground cracks. A four-station network, installed in March, showed a shallow (1-3 km) southeast-northwest-oriented reverse fault, consistent with global and regional Centroid Moment Tensor (CMT) solutions. The rupture size (5 km long x 3 km wide) and 1 m slip (from Interferometric Synthetic Aperture Radar data) indicate a stress drop of 5-12 MPa, larger than the average in mid-plate South America. The large non-double-couple (DC) component of all CMT solutions is probably due to a complex rupture geometry, suggested by the aftershock distribution. None of the usual hypotheses to explain intraplate seismicity (weakness zones, stress concentration, and flexural stresses) is applicable to this event. There are no signs of crustal weakness zones: the major Paleoproterozoic faults trend southwest-northeast, orthogonal to the southeast-northwest rupture; the Mesozoic Takutu graben is 65 km away. None of the surface-wave tomographies indicate lithospheric thinning. Free-air anomalies near the epicenter have average values and do not indicate crustal loads increasing stresses locally. In the isolated epicentral area there is no mining activity nor hydroelectric reservoir to induce seismicity. No prior seismogenic feature was found to explain this activity.
Název v anglickém jazyce
The 2021 Mw 5.6 Earthquake in the Guyana Shield, South America: An Intraplate Event with No Reason to Occur
Popis výsledku anglicky
In 31 January 2021, an Mw 5.6 earthquake occurred in the Guyana shield, causing damage to adobe houses and ground cracks. A four-station network, installed in March, showed a shallow (1-3 km) southeast-northwest-oriented reverse fault, consistent with global and regional Centroid Moment Tensor (CMT) solutions. The rupture size (5 km long x 3 km wide) and 1 m slip (from Interferometric Synthetic Aperture Radar data) indicate a stress drop of 5-12 MPa, larger than the average in mid-plate South America. The large non-double-couple (DC) component of all CMT solutions is probably due to a complex rupture geometry, suggested by the aftershock distribution. None of the usual hypotheses to explain intraplate seismicity (weakness zones, stress concentration, and flexural stresses) is applicable to this event. There are no signs of crustal weakness zones: the major Paleoproterozoic faults trend southwest-northeast, orthogonal to the southeast-northwest rupture; the Mesozoic Takutu graben is 65 km away. None of the surface-wave tomographies indicate lithospheric thinning. Free-air anomalies near the epicenter have average values and do not indicate crustal loads increasing stresses locally. In the isolated epicentral area there is no mining activity nor hydroelectric reservoir to induce seismicity. No prior seismogenic feature was found to explain this activity.
Klasifikace
Druh
J<sub>imp</sub> - Článek v periodiku v databázi Web of Science
CEP obor
—
OECD FORD obor
10500 - Earth and related environmental sciences
Návaznosti výsledku
Projekt
—
Návaznosti
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Ostatní
Rok uplatnění
2025
Kód důvěrnosti údajů
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Údaje specifické pro druh výsledku
Název periodika
The Seismic Record
ISSN
2694-4006
e-ISSN
2694-4006
Svazek periodika
5
Číslo periodika v rámci svazku
2
Stát vydavatele periodika
US - Spojené státy americké
Počet stran výsledku
11
Strana od-do
228-238
Kód UT WoS článku
001529871300001
EID výsledku v databázi Scopus
2-s2.0-105010061130