Search results
Results from the WOW.Com Content Network
The presumed seismically and tectonically active portion of this fracture zone is known as the Heirtzler transform fault and divides a portion of the Pacific-Antarctic Ridge where spreading rates increase towards its axial north from 56 to 66 mm (2.2 to 2.6 in)/year over a distance of 650 km (400 mi). [3]
Some use the term "transform fault" to describe the seismically and tectonically active portion of a fracture zone after John Tuzo Wilson's concepts first developed with respect to the Mid-Atlantic Ridge. [2] The term fracture zone has a distinct geological meaning, but it is also used more loosely in the naming of some oceanic features.
Seismotectonics is the study of the relationship between the earthquakes, active tectonics and individual faults of a region. It seeks to understand which faults are responsible for seismic activity in an area by analysing a combination of regional tectonics, recent instrumentally recorded events, accounts of historical earthquakes and geomorphological evidence.
The accommodation of this plate configuration results in a transform boundary along the Mendocino fracture zone, and a divergent boundary at the Gorda Ridge. [2] [3] This area is tectonically active historically and today. The Cascadia subduction zone is capable of producing megathrust earthquakes on the order of MW 9.0.
Tectonic subsidence is the sinking of the Earth's crust on a large scale, relative to crustal-scale features or the geoid. [1] The movement of crustal plates and accommodation spaces produced by faulting [2] brought about subsidence on a large scale in a variety of environments, including passive margins, aulacogens, fore-arc basins, foreland basins, intercontinental basins and pull-apart basins.
The thickness of alluvial fans forming due to basin margins are influenced tectonically. [3] If the alluvial fan gets thicker and the grains become more coarse heading up the fan, this indicates that the basin margin is tectonically active and the building of the alluvial fan being more active than the deposition rate.
The zone is characterized by active compression during the Algoman orogeny (about ), a pulling-apart (extensional) tectonics (2,450 to 2,100 million years ago), a second compression during the Penokean orogeny (1,900 to 1,850 million years ago), a second extension during Middle Proterozoic time (1,600 million years ago) and minor reactivation ...
In geology, a nappe or thrust sheet is a large sheetlike body of rock that has been moved more than 2 km (1.2 mi) [1] or 5 km (3.1 mi) [2] [3] above a thrust fault from its original position. Nappes form in compressional tectonic settings like continental collision zones or on the overriding plate in active subduction zones.