TY - JOUR A1 - Melnick, Daniel A1 - Li, Shaoyang A1 - Moreno, Marcos A1 - Cisternas, Marco A1 - Jara-Munoz, Julius A1 - Wesson, Robert A1 - Nelson, Alan A1 - Baez, Juan Carlos A1 - Deng, Zhiguo T1 - Back to full interseismic plate locking decades after the giant 1960 Chile earthquake JF - Nature Communications N2 - Great megathrust earthquakes arise from the sudden release of energy accumulated during centuries of interseismic plate convergence. The moment deficit (energy available for future earthquakes) is commonly inferred by integrating the rate of interseismic plate locking over the time since the previous great earthquake. But accurate integration requires knowledge of how interseismic plate locking changes decades after earthquakes, measurements not available for most great earthquakes. Here we reconstruct the post-earthquake history of plate locking at Guafo Island, above the seismogenic zone of the giant 1960 (M-w = 9.5) Chile earthquake, through forward modeling of land-level changes inferred from aerial imagery (since 1974) and measured by GPS (since 1994). We find that interseismic locking increased to similar to 70% in the decade following the 1960 earthquake and then gradually to 100% by 2005. Our findings illustrate the transient evolution of plate locking in Chile, and suggest a similarly complex evolution elsewhere, with implications for the time- and magnitude-dependent probability of future events. Y1 - 2018 U6 - https://doi.org/10.1038/s41467-018-05989-6 SN - 2041-1723 VL - 9 PB - Nature Publ. Group CY - London ER - TY - INPR A1 - Melnick, Daniel A1 - Moreno, Marcos A1 - Motagh, Mahdi A1 - Cisternas, Marco A1 - Wesson, Robert L. T1 - Splay fault slip during the M-w 8.8 2010 maule Chile earthquake reply T2 - Geology Y1 - 2013 U6 - https://doi.org/10.1130/G34825Y.1 SN - 0091-7613 SN - 1943-2682 VL - 41 IS - 12 SP - E310 EP - E310 PB - American Institute of Physics CY - Boulder ER - TY - JOUR A1 - Melnick, Daniel A1 - Moreno, Marcos A1 - Motagh, Mahdi A1 - Cisternas, Marco A1 - Wesson, Robert L. T1 - Splay fault slip during the M-w 8.8 2010 Maule Chile earthquake JF - Geology N2 - Splay faults are thrusts that emerge from the plate boundaries of subduction zones. Such structures have been mapped at several convergent margins and their activity commonly ascribed to large megathrust earthquakes. However, the behavior of splay faults during the earthquake cycle is poorly constrained because typically these structures are located offshore and are difficult to access. Here we use geologic mapping combined with space and land geodesy, as well as offshore sonar data, to document surface-fault ruptures and coastal uplift at Isla Santa Maria in south-central Chile (37 degrees S) caused by the 27 February 2010 Maule earthquake (M-w 8.8). During the earthquake, the island was tilted parallel to the margin, and normal faults ruptured the surface and adjacent ocean bottom. We associate tilt and crestal normal faulting with growth of an anticline above a blind reverse fault rooted in the Nazca-South America plate boundary, which slipped during the Maule earthquake. The splay fault system has formed in an area of reduced coseismic plate-boundary slip, suggesting that anelastic deformation in the upper plate may have restrained the 2010 megathrust rupture. Surface fault breaks were accompanied by prominent discharge of fluids. Our field observations support the notion that splay faulting may frequently complement and influence the rupture of subduction-zone earthquakes. Y1 - 2012 U6 - https://doi.org/10.1130/G32712.1 SN - 0091-7613 VL - 40 IS - 3 SP - 251 EP - 254 PB - American Institute of Physics CY - Boulder ER - TY - JOUR A1 - Wesson, Robert L. A1 - Melnick, Daniel A1 - Cisternas, Marco A1 - Moreno, Marcos A1 - Ely, Lisa L. T1 - Vertical deformation through a complete seismic cycle at Isla Santa Maria, Chile JF - Nature geoscience N2 - Individual great earthquakes are posited to release the elastic strain energy that has accumulated over centuries by the gradual movement of tectonic plates(1,2). However, knowledge of plate deformation during a complete seismic cycle-two successive great earthquakes and the intervening interseismic period-remains incomplete(3). A complete seismic cycle began in south-central Chile in 1835 with an earthquake of about magnitude 8.5 (refs 4,5) and ended in 2010 with a magnitude 8.8 earthquake(6). During the first earthquake, an uplift of Isla Santa Maria by 2.4 to 3m was documented(4,5). In the second earthquake, the island was uplifted(7) by 1.8 m. Here we use nautical surveys made in 1804, after the earthquake in 1835 and in 1886, together with modern echo sounder surveys and GPS measurements made immediately before and after the 2010 earthquake, to quantify vertical deformation through the complete seismic cycle. We find that in the period between the two earthquakes, Isla Santa Maria subsided by about 1.4 m. We simulate the patterns of vertical deformation with a finite-element model and find that they agree broadly with predictions from elastic rebound theory(2). However, comparison with geomorphic and geologic records of millennial coastline emergence(8,9) reveal that 10-20% of the vertical uplift could be permanent. Y1 - 2015 U6 - https://doi.org/10.1038/NGEO2468 SN - 1752-0894 SN - 1752-0908 VL - 8 IS - 7 SP - 547 EP - U157 PB - Nature Publ. Group CY - New York ER - TY - GEN A1 - Melnick, Daniel A1 - Li, Shaoyang A1 - Moreno, Marcos A1 - Cisternas, Marco A1 - Jara-Muñoz, Julius A1 - Wesson, Robert A1 - Nelson, Alan A1 - Báez, Juan Carlos A1 - Deng, Zhiguo T1 - Back to full interseismic plate locking decades after the giant 1960 Chile earthquake T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Great megathrust earthquakes arise from the sudden release of energy accumulated during centuries of interseismic plate convergence. The moment deficit (energy available for future earthquakes) is commonly inferred by integrating the rate of interseismic plate locking over the time since the previous great earthquake. But accurate integration requires knowledge of how interseismic plate locking changes decades after earthquakes, measurements not available for most great earthquakes. Here we reconstruct the post-earthquake history of plate locking at Guafo Island, above the seismogenic zone of the giant 1960 (M-w = 9.5) Chile earthquake, through forward modeling of land-level changes inferred from aerial imagery (since 1974) and measured by GPS (since 1994). We find that interseismic locking increased to similar to 70% in the decade following the 1960 earthquake and then gradually to 100% by 2005. Our findings illustrate the transient evolution of plate locking in Chile, and suggest a similarly complex evolution elsewhere, with implications for the time- and magnitude-dependent probability of future events. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 678 KW - south-central Chile KW - continuous GPS measurements KW - andean subduction zone KW - finite-element model KW - 2010 M8.8 maule KW - postseismic deformation KW - megathrust earthquake KW - afterslip KW - slip KW - resolution Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-425723 SN - 1866-8372 IS - 678 ER -