Extension and Dynamics of the Andes Inferred From the 2016 Parina (Huarichancara) Earthquake

摘要: The Mw 6.1 2016 Parina earthquake led to extension of the south Peruvian Andes along a normal fault with evidence Holocene slip. We use interferometric synthetic aperture radar, seismology, and field mapping determine source model for this event show that at is oriented NE‐SW, which parallel shortening direction in adjacent sub‐Andean lowlands. In addition, we models GPS data demonstrate within sub‐Andes topographic gradients. Both observations imply forces resulting from spatial variations gravitational potential energy are important controlling geometry deformation Andes. calculate horizontal per unit length acting between South America due these contrasts be 4–8 ×1012 N/m strike mountain range. Normal faulting implies Peru have reached maximum elevation can supported by transmitted across foreland, requires foreland faults an effective coefficient friction urn:x-wiley:jgrb:media:jgrb53009:jgrb53009-math-00010.2. Additionally, onset parts central following orogen‐wide compression late Miocene suggests there has been change force balance mountains. propose on weak detachment Andean since ∼5–9 Ma reduced shear tractions base upper crust eastern Andes, leading highest