Discovering the Čirá-Kopanina Fault: Bridging the Gap between Surface Evidence and Seismic Activity

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985891%3A_____%2F25%3A00637947" target="_blank" >RIV/67985891:_____/25:00637947 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11310/25:10506142

Výsledek na webu

<a href="https://doi.org/10.2113/2024/lithosphere_2024_192" target="_blank" >https://doi.org/10.2113/2024/lithosphere_2024_192</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.2113/2024/lithosphere_2024_192" target="_blank" >10.2113/2024/lithosphere_2024_192</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Discovering the Čirá-Kopanina Fault: Bridging the Gap between Surface Evidence and Seismic Activity

Popis výsledku v původním jazyce

The West Bohemia region in Czechia is well known for its frequent seismic activity, particularly earthquake swarms with magnitudes up to 3-4. Seismicity has been documented since the sixteenth century, with pronounced activity since 1985. Earthquakes concentrate in the Nov & yacute, Kostel area where hypocenters align along a N-S trending fault zone over 15 km long and at depths of 6-13 km. Despite this activity, a clear surface trace of the responsible fault has remained elusive. This study reports the discovery and investigation of a surface manifestation of the & Ccaron,ir & aacute,-Kopanina fault (& Ccaron,KF), which aligns with the Nov & yacute, Kostel focal zone (NKFZ). A multidisciplinary approach, integrating geomorphological, geophysical, and seismological analyses, was used to explore the & Ccaron,KF trace and its near-surface structure. Aligned geomorphological features, including a NNW-trending scarp and linear springs and wet areas, suggest a fault trace extending southward from & Ccaron,ir & aacute, village. A combined geophysical survey, including electrical resistivity tomography (ERT), shallow seismic refraction, gravity survey, and electromagnetic induction, confirmed the presence and characteristics of the fault. ERT data revealed a continuous zone, up to 200 m wide, of low resistivity interpreted as fractured, weathered, water-saturated rocks, indicating multiple parallel fault strands. Measurements across the prominent scarp at & Ccaron,ir & aacute, village consistently confirmed the fault zone's presence with all applied methods. Relocation of earthquake hypocenters (1991-2022) showed a narrow, steeply dipping fault zone striking 169 degrees and descending from 6 to 13 km depth. Subparallel and oblique segments dipping west support the interpretation that the & Ccaron,KF trace represents the surface expression of the NKFZ. The fault scarp implies past surface-rupturing earthquakes, and both historical ruptures and present-day swarms with magnitudes up to ML 5 likely occur within the same fault system. These findings emphasize the & Ccaron,KF's recent tectonic activity and its role in regional seismic hazard assessment.

Název v anglickém jazyce

Discovering the Čirá-Kopanina Fault: Bridging the Gap between Surface Evidence and Seismic Activity

Popis výsledku anglicky

The West Bohemia region in Czechia is well known for its frequent seismic activity, particularly earthquake swarms with magnitudes up to 3-4. Seismicity has been documented since the sixteenth century, with pronounced activity since 1985. Earthquakes concentrate in the Nov & yacute, Kostel area where hypocenters align along a N-S trending fault zone over 15 km long and at depths of 6-13 km. Despite this activity, a clear surface trace of the responsible fault has remained elusive. This study reports the discovery and investigation of a surface manifestation of the & Ccaron,ir & aacute,-Kopanina fault (& Ccaron,KF), which aligns with the Nov & yacute, Kostel focal zone (NKFZ). A multidisciplinary approach, integrating geomorphological, geophysical, and seismological analyses, was used to explore the & Ccaron,KF trace and its near-surface structure. Aligned geomorphological features, including a NNW-trending scarp and linear springs and wet areas, suggest a fault trace extending southward from & Ccaron,ir & aacute, village. A combined geophysical survey, including electrical resistivity tomography (ERT), shallow seismic refraction, gravity survey, and electromagnetic induction, confirmed the presence and characteristics of the fault. ERT data revealed a continuous zone, up to 200 m wide, of low resistivity interpreted as fractured, weathered, water-saturated rocks, indicating multiple parallel fault strands. Measurements across the prominent scarp at & Ccaron,ir & aacute, village consistently confirmed the fault zone's presence with all applied methods. Relocation of earthquake hypocenters (1991-2022) showed a narrow, steeply dipping fault zone striking 169 degrees and descending from 6 to 13 km depth. Subparallel and oblique segments dipping west support the interpretation that the & Ccaron,KF trace represents the surface expression of the NKFZ. The fault scarp implies past surface-rupturing earthquakes, and both historical ruptures and present-day swarms with magnitudes up to ML 5 likely occur within the same fault system. These findings emphasize the & Ccaron,KF's recent tectonic activity and its role in regional seismic hazard assessment.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

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OECD FORD obor

10505 - Geology

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Lithosphere

ISSN

1941-8264

e-ISSN

1947-4253

Svazek periodika

2024

Číslo periodika v rámci svazku

15

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

24

Strana od-do

192

Kód UT WoS článku

001536327300001

EID výsledku v databázi Scopus

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