Earthquake Investigations at the Dickey-Lincoln School Damsites, Maine

The Dickey-Lincoln School damsites are less than 50 miles from an area along the St. Lawrence River which has experienced some of the most severe earthquakes in North America. A geological and seismological investigation was made of the region in order to determine the hazards from earthquakes at the damsites. No active faults were found in the general area of the damsites. The source area of potentially severe earthquakes was found to be restricted to a narrow band that follows the St. Lawrence River. This band was designated as Zone A. The boundary of Zone A is located U5 miles from the damsites. Zone B, with less seismic risk, borders Zone A and is Uo miles from the damsites. The damsites are situated in Zone C, which has the least seismic risk in the region. Zone D, with a level of seismic risk between that of Zones B and C, occurs 75 miles southeast of the damsites. The most severe ground motion at the damsites was interpreted to be from an earthquake in Zone A attenuated over a distance of 45 miles. Such movement is interpreted to have a peak acceleration of 0.35 g, a peak velocity of 65 cm/sec, and a peak displacement of 22 cm. The duration of shaking is estimated at 18 sec. Accelerographs are recommended for scaling in order to develop time histories of bedrock ground motion for dynamic analyses

Seismic risk assessment for developing countries : Pakistan as a case study

Modern Earthquake Risk Assessment (ERA) methods usually require seismo-tectonic information for Probabilistic Seismic Hazard Assessment (PSHA) that may not be readily available in developing countries. To bypass this drawback, this paper presents a practical event-based PSHA method that uses instrumental seismicity, available historical seismicity, as well as limited information on geology and tectonic setting. Historical seismicity is integrated with instrumental seismicity to determine the long-term hazard. The tectonic setting is included by assigning seismic source zones associated with known major faults. Monte Carlo simulations are used to generate earthquake catalogues with randomized key hazard parameters. A case study region in Pakistan is selected to demonstrate the effectiveness of the method. The results indicate that the proposed method produces seismic hazard maps consistent with previous studies, thus being suitable for generating such maps in regions where limited data are available. The PSHA procedure is developed as an integral part of an ERA framework named EQRAM. The framework is also used to determine seismic risk in terms of annual losses for the study region

U.S. Waterways Experiment Station Reports

Final report discussing a facility built to test californium-252 in research on moisture, density, and other properties of soil and rock in relation to engineering characteristics