Showing papers in "Advances in Geophysics in 2001"
TL;DR: In this paper, the authors present a theoretical framework for earthquake cycles based on calculating the stress changes caused by one event and assessing where and what mechanism of earthquakes these changes may promote, which is different from investigating the dynamic rupture growth requiring the reconstruction of the spatiotemporal evolution of the stress on the fault plane.
Abstract: Publisher Summary This chapter discusses the recent developments in understanding how earthquakes interact with each other. The new theoretical framework for earthquake cycles is based on calculating the stress changes caused by one event and assessing where and what mechanism of earthquakes these changes may promote. For studying such stress interaction, the computation of the stress field outside a rupturing fault is analyzed. This is different from investigating the dynamic rupture growth requiring the reconstruction of the spatiotemporal evolution of the stress on the fault plane. The chapter discusses the theoretical background of earthquake sequences and reviews some of the simple examples that allowed stress coupling concepts to be accepted. The success of simple stress modeling led to the introduction of several modifications, adaptations, and refinements of the ideas.
304 citations
TL;DR: In this article, a deterministic approach based on the assumption that several earthquakes can occur within a predefined seismic zone, represents a conservative definition of seismic hazard for preevent localized planning for disaster mitigation, over a broad range of periods.
Abstract: Publisher Summary The ability to estimate accurately seismic hazard at very low probability of exceedance may be important in protecting special objects in the built environment against rare earthquakes. The deterministic approach, based upon the assumption that several earthquakes can occur within a predefined seismic zone, represents a conservative definition of seismic hazard for preevent localized planning for disaster mitigation, over a broad range of periods. Computation of realistic synthetic seismograms, using methods that take into account source, propagation, and site effects, and utilizing the huge amount of available geological, geophysical, and geotechnical data provides a powerful and economically valid scientific tool for seismic zonation and microzanation. First-order zonations can be made at regional scale, considering average structural models and a set of sources with damaging potential distributed within the identified seismogenic areas. Seismic microzonations of urban areas can be performed even more accurately when the required geotechnical data are available, so that local site effects can be effectively modeled.
288 citations
TL;DR: In this article, the authors provide an overview of the seismic discrimination between underground explosions and seismic events originating in deep mines and show that seismic events induced by mining are not uniformly distributed in either space or time.
Abstract: Publisher Summary During the past several years, seismic monitoring has been expanded in several mining districts, a number of new techniques have been introduced, and new significant results have been obtained in studies of the seismic events induced by mining New techniques in seismic monitoring in mines, geological and mining factors affecting seismicity, source parameters and their scaling relations, and shearing versus non-shearing source mechanisms are briefly described in the chapter Statistical techniques and methods that are used extensively in recent years in studies of seismicity in mines, especially for seismic hazard assessment are discussed This chapter provides an overview of the seismic discrimination between underground explosions and seismic events originating in deep mines Seismic events induced by mining are not uniformly distributed in either space or time Extensive studies performed on the space-time-energy distributions of seismic events in mines show that the tendency to form nests, swarms, and clusters is commonly observed Seismicity in mines is strongly affected by local geology and tectonics, and by interaction between mining and crustal state of stress on a local and regional scale
117 citations
TL;DR: In this article, the authors provide a brief review of major characteristics of reservoir structures and lithologies serving as a guide to reservoir selection for CO 2 disposal in aquifers and reservoirs.
Abstract: Publisher Summary This chapter provides a brief review of major characteristics of reservoir structures and lithologies serving as a guide to reservoir selection for CO 2 disposal. The chapter focuses on existing experience and uncertainties in reservoir characterization and response to CO 2 injection and long-term containment of sequestration sites. Special issues germane to CO 2 disposal arise in the assessment of depleted reservoirs, whose properties are known to have changed during single or repeated pore-pressure drawdown and fluid redistribution. Oil and gas reservoirs and aquifers share some common geometric elements. Generally, both are tabular bodies in which the fluid flow is constrained by upper and lower less-permeable lithologies. Primary aspects of CO 2 sequestration in geologic formations include the geohydrologic characterization, injection behavior, and long-term containment of supercritical CO 2 for storage in aquifers and reservoirs. The efficiency of a CO 2 enhanced oil-recovery flood depends strongly on the equilibrium phase behavior of mixtures of CO 2 with the oil.
89 citations