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Deformación lenta y menor riesgo sísmico en la nueva zona sísmica de Madrid
1Department of Geological Sciences, Northwestern University, Evanston, IL, 60208, USA. Department of Geology, Grand Valley State University, Allendale, MI 49401, USA. Department of Geological Sciences, University of Missouri, Columbia, MO.
Science (New York, N.Y.)
|April 24, 1999
Resumen
Los datos del Sistema de Posicionamiento Global (GPS) revelan movimiento mínimo en la zona sísmica de Nueva Madrid (NMSZ). Esto sugiere que el riesgo sísmico de grandes terremotos en la NMSZ puede estar sobreestimado, desafiando suposiciones anteriores.
Área de la Ciencia:
- La geofísica es la geofísica.
- Sismología Sismología Sismología.
- La tectónica de placas es la tectónica de placas.
Sus antecedentes:
- La zona sísmica de Nueva Madrid (NMSZ) en el centro de los Estados Unidos es una región de actividad sísmica históricamente significativa.
- Las evaluaciones anteriores del peligro sísmico en la NMSZ a menudo han asumido magnitudes altas para los terremotos grandes pasados.
Objetivo del estudio:
- Reevaluar el riesgo sísmico en la zona sísmica de Nuevo Madrid (NMSZ) mediante el análisis de los datos geodésicos actuales.
- Evaluar los intervalos de repetición de los grandes terremotos en la NMSZ sobre la base de nuevas evidencias.
Principales métodos:
- Análisis de las mediciones continuas del Sistema de Posicionamiento Global (GPS) en toda la NMSZ.
- Comparación de los datos GPS de NMSZ con los datos GPS de toda la placa.
- Aplicación de las relaciones frecuencia-magnitud a los datos de sismicidad.
Principales resultados:
- Las mediciones de GPS indican poco o ningún movimiento de la corteza dentro de la NMSZ.
- Estos hallazgos son consistentes con los datos GPS de toda la placa que no muestran movimiento significativo.
- El intervalo de recurrencia implícito para los terremotos de magnitud 8 en la NMSZ supera los 2500 años, más largo de lo que se suponía anteriormente.
Conclusiones:
- El peligro sísmico planteado por grandes terremotos en la NMSZ puede ser sobreestimado.
- Los grandes terremotos pasados en la NMSZ podrían haber sido más pequeños de lo que se cree comúnmente.
- Los datos geodésicos actuales no apoyan los modelos de alta tasa de deslizamiento para la NMSZ.
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