The 2011 Mw 9.0 Tohoku earthquake generated an aftershock sequence that affected a large part of northern Honshu, and has given rise to widely divergent forecasts of changes in earthquake occurrence probabilities in northern Honshu. The objective of this review is to assess these forecasts as they relate to potential changes in the occurrence probabilities of damaging earthquakes in the Kanto R...

b-Value Variations Preceding the Devastating, 1999 Earthquake, near Izmit, Turkey Sara Andersson The potential of temporal b-value variations as an intermediate-term (weeks to months) earthquake precursor was investigated in the western portion of the North Anatolian Fault Zone (NAFZ), between January 1982 to December 2004. The focus of the study is on the devastating, 1999 earthquake, near Izm...

The tectonically complex San Francisco Bay Region (SFBR) contains both known and unidentified faults that produce a broad range of earthquake sizes at different rates of occurrence. In this chapter we use fault zone information developed in the previous chapter to construct an earthquake source model that describes long-term rates of earthquake production in the SFBR. Specifically, this SFBR ea...

Large deep-focus earthquakes (magnitude> 7.0, depth> 500 km) have exhibited strong seasonality in their occurrence times since the beginning of global earthquake catalogs. Of 60 such events from 1900 to the present, 42 have occurred in the middle half of each year. The seasonality appears strongest in the northwest Pacific subduction zones and weakest in the Tonga region. Taken at face value, t...

The physics of an earthquake is a subject with many unknowns. It is true that we have a good understanding of the propagation of seismic waves through the Earth and that given a large set of seismographic records we are able to reconstruct a posteriori the history of the fault rupture (the origin of the waves). However, when we consider the physical processes which lead to the initiation of a r...

On 3 April 2017, a Mw 6.5 earthquake occurred in Botswana, representing the secondstrongest earthquake registered since 1949. Such an intraplate event occurred in a low seismic hazard area and was suspected to be an artificial earthquake induced by nearby anthropogenic activities (gas extraction). The possible relation between anthropogenic activities and the earthquake occurrence has been qual...

In this study, we extract earthquake co-occurrence patterns for investigating mechanical interactions in the affected areas. To extract seismic patterns, both co-occurrence among seismic events in the event sequence and distances between the hypocenters to find hot spots must be considered. Most previous researches, however, have considered only one of these aspects. In contrast, we utilized co...

People in the locality of earthquakes are publishing anecdotal information about the shaking within seconds of their occurrences via social network technologies, such as Twitter. In contrast, depending on the size and location of the earthquake, scientific alerts can take between two to twenty minutes to publish. We describe TED (Twitter Earthquake Detector) a system that adopts social network ...

The Regional Earthquake Likelihood Models (RELM) test of earthquake forecasts in California was the first competitive evaluation of forecasts of future earthquake occurrence. Participants submitted expected probabilities of occurrence of M ≥ 4.95 earthquakes in 0.1° × 0.1° cells for the period 1 January 1, 2006, to December 31, 2010. Probabilities were submitted for 7,682 cells in California an...