Geodynamics of the Wadati-Benioff zone earthquakes: The 2004 Sumatra earthquake and other great earthquakes
Geodynamics of the Wadati-Benioff zone earthquakes: The 2004 Sumatra earthquake and other great earthquakes
| dc.creator | Scalera, Giancarlo | |
| dc.date | 2010-10-18 | |
| dc.date.accessioned | 2018-03-16T15:55:50Z | |
| dc.date.available | 2018-03-16T15:55:50Z | |
| dc.identifier | http://ojs.unam.mx/index.php/geofisica/article/view/40195 | |
| dc.identifier.uri | http://repositorioslatinoamericanos.uchile.cl/handle/2250/1203660 | |
| dc.description | The displacement of the Earth’s instantaneous rotation pole – observed at ASI of Matera, Italy – the seismic data (USGS) in the two days following the main shock, the high frequency P-wave radiation, the geomorphologic data, and the satellite data of uplift/subsidence of the coasts (IGG) converge toward a new interpretation of the Great Sumatran earthquake (TU=26 December 2004 - 00h 58m, Lat=3.3°N, Lon=95.8°E, H=10 km, M=9.3) based on the second conjugate – nearly vertical – CMT fault plane solution. In a non-double-couple treatment that considers non-negligible non-elastic contributions to the earthquake phenomena, only a nearly vertical fault can explain both high values of seismic moment and the ≈3.0 mas (≈10 cm) polhody displacement toward an azimuth exactly opposite to the epicentre azimuth. Case-histories of great earthquakes are then reviewed to highlight the overall analogies. The similarity of the vertical displacements shown by these earthquakes (Chile 1960, Alaska 1964, …) leads to a common interpretation necessitating resort to a prevailing uprising of lithospheric material. This interpretation is supported by the inspection of the irregularities of the hypocentre distribution along the Wadati-Benioff zones. Moreover, in the case of great South American earthquakes, a volcanic eruptions-earthquakes correlation is clearly recognisable. A thorough revision of the pure elastic rebound model of great earthquakes occurrence and a complete overcoming of the large scale subduction concept is then needed. | en-US |
| dc.description | Se presenta una nueva interpretación del sismo de Sumatra de 2004 en base al desplazamiento del polo de rotación de la Tierra observado en Matera, Italia; los datos sísmicos para los dos días siguientes al sismo; la radiación P de alta frecuencia, la geomorfología y los datos satelitales IGG sobre hundimiento/levantamiento costeros. La solución del mecanismo CMT admite una falla casi vertical que explicaría el elevado momento sísmico y el desplazamiento de 10 cm del polhody en dirección opuesta al azimut del epicentro. Se revisan las historias de caso para importantes sismos históricos y se concluye que los desplazamientos para Chile 1960 y Alaska 1964 son similares, implicando un surgimiento de material litosférico confirmado con las irregularidades observadas en la distribución de hipocentros en la zona de Wadati-Benioff. En los sismos sudamericanos también se observa una correlación entre sismos y erupciones volcánicas. Se argumenta a favor de una revisión del modelo original del rebote elástico y del concepto de subducción a gran escala. | es-ES |
| dc.format | application/pdf | |
| dc.language | spa | |
| dc.publisher | Instituto de Geofísica | es-ES |
| dc.relation | http://ojs.unam.mx/index.php/geofisica/article/view/40195/36588 | |
| dc.source | Geofísica Internacional; Vol 46, No 1 (2007) | es-ES |
| dc.source | 0016-7169 | |
| dc.subject | Geodinámica; corrimiento polar; grandes sismos; erupciones volcánicas; expansión de la tierra | es-ES |
| dc.subject | Geodynamics; polar motion; great earthquakes; volcanic eruptions; expanding Earth | en-US |
| dc.title | Geodynamics of the Wadati-Benioff zone earthquakes: The 2004 Sumatra earthquake and other great earthquakes | en-US |
| dc.title | Geodynamics of the Wadati-Benioff zone earthquakes: The 2004 Sumatra earthquake and other great earthquakes | es-ES |
| dc.type | Artículos de revistas | |
| dc.type | Artículos de revistas |