Epicenter distribution and magnitude of earthquakes in fold-thrust belts: insights from sandbox models
2000 (English)In: Geophysical Research Letters, ISSN 0094-8276, ISSN 0094-8276, Vol. 27, no 2, 273-276 p.Article in journal (Refereed) Published
Scaled analogue models are used to illustratethe eect of basal friction and erosion on fault activity andhence on epicentre distribution and magnitude of earth-quakes in the sedimentary cover of active fold-thrust belts.Model results suggest that in fold-thrust belts shortenedabove low-friction ductile decollements (rock salt or over-pressured mudstone), low- to moderate-magnitude earth-quakes (Mw=5:3−5:6), distributed over a wide area, occuralong several long-lived thrust faults. Conversely, in areasshortened above high-friction decollements large-magnitudeearthquakes (Mw=6:6−6:8), distributed over a narrowzone are likely to occur along few short- lived thrust ramps.Calculated magnitude of earthquakes from models and theirdistribution are in agreement with recorded earthquake pat-tern from the Zagros mountain belt, which is partially short-ened above a ductile decollement of Hormuz salt formation.Model results also showed that erosion reactivates older in-active thrusts and promotes formation of out-of-sequencethrusts.
Place, publisher, year, edition, pages
American Geophysical Union (AGU), 2000. Vol. 27, no 2, 273-276 p.
WEDGES; HIMALAYAS; BEHAVIOR; GEOMETRY; SYSTEMS; IRAN; SALT
Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:uu:diva-37780OAI: oai:DiVA.org:uu-37780DiVA: diva2:65679