Title: Segmentation and supercycles: A catalog of earthquake rupture patterns from well-studied faults worldwide<\/p>\n
Abstract:
\nAfter more than 100 years of earthquake research, earthquake forecasting, which relies on knowledge of past fault rupture patterns, has become the foundation for societal defense against seismic natural disasters.\u00a0 A concept that has come into focus more recently is that rupture segmentation and cyclicity can be complex, and that a characteristic earthquake model is too simple to adequately describe much of fault behavior.\u00a0 Nevertheless, recognizable patterns in earthquake recurrence emerge from long, high resolution, spatially distributed chronologies.\u00a0 Researchers now seek to discover the maximum, minimum, and typical rupture areas; the distribution, variability, and spatial applicability of recurrence intervals; and patterns of earthquake clustering in space and time.\u00a0 The term \u201csupercycle\u201d has been used to describe repeating longer periods of elastic strain accumulation and release that involve multiple fault ruptures.\u00a0 However, this term has become very broadly applied, lumping together several distinct phenomena that likely have disparate underlying causes.\u00a0 I divide earthquake cycle behavior into four major classes that have different implications for seismic hazard and fault mechanics: 1) quasi-periodic similar ruptures, 2) clustered similar ruptures, 3) clustered complementary ruptures \/ rupture cascades, and 4) superimposed cycles.\u00a0 \u201cSegmentation\u201d is likewise an ambiguous term; we identify \u201cmaster segments\u201d and \u201casperities\u201d as defined by barriers to fault rupture.\u00a0 These barriers may be persistent (rarely or never traversed), frequent (occasionally traversed), or ephemeral (changing location from cycle to cycle).\u00a0 I present a catalog of the historical and paleoseismic evidence that currently exists for each of these types of behavior on major well-studied faults worldwide.\u00a0 Due to the unique level of paleoseismic and paleogeodetic detail provided by the coral microatoll technique, the Sumatran Sunda megathrust provides one of the most complete records over multiple earthquake rupture cycles.\u00a0 Long historical records of earthquakes along the South American and Japanese subduction zones are also vital contributors to our catalog, along with additional data compiled from subduction zones in Cascadia, Alaska, and Middle America, as well as the North Anatolian and Dead Sea strike-slip faults in the Middle East.\u00a0 This compilation reveals that persistent and frequent barriers, rupture cascades, superimposed cycles, and quasi-periodic similar ruptures are common features of most major faults.\u00a0 Clustered similar ruptures do not appear to be common, but broad overlap zones between neighboring segments do occur. Barrier regions accommodate slip through reduced interseismic coupling, slow slip events, and\/or smaller more localized ruptures, and are frequently associated with structural features such as subducting seafloor relief or fault trace discontinuities.\u00a0 This catalog of observations provides a basis for exploring and modeling root causes of rupture segmentation and cycle behavior. We expect that researchers will recognize similar behavior styles on other major faults around the world.<\/p>\n","protected":false},"excerpt":{"rendered":"