Frequency of earthquakes in California*

Gutenberg, B.; Richter, C. F.

doi:10.1785/bssa0340040185

Cited by 3,437 publications

(707 citation statements)

References 1 publication

Supporting

Mentioning

538

Contrasting

Unclassified

Order By: Relevance

“…The summation performed over the contributions of all the previous shocks, that is the second term in the right hand side of the ETES rate (1), provides the time-varying "triggered" aftershock component of the seismic sequence. According to the ETES model, the magnitude distribution of both the spontaneous and triggered components of rate ( 1) is separable with respect to time and space, and it is given by the well-known decreasing exponential Gutenberg-Richter law (Gutenberg and Richter, 1944)…”

Section: Etes Modelmentioning

confidence: 99%

An Operational Earthquake Forecasting Experiment for Israel: Preliminary Results

et al. 2021

View full text Add to dashboard Cite

Operational Earthquake Forecasting (OEF) aims to deliver timely and reliable forecasts that may help to mitigate seismic risk during earthquake sequences. In this paper, we build the first OEF system for the State of Israel, and we evaluate its reliability. This first version of the OEF system is composed of one forecasting model, which is based on a stochastic clustering Epidemic Type Earthquake Sequence (ETES) model. For every day of the forecasting time period, January 1, 2016 - November 15, 2020, the OEF-Israel system produces a weekly forecast for target earthquakes with local magnitudes greater than 4.0 and 5.5 in the entire State of Israel. Specifically, it provides space-time-dependent seismic maps of the weekly probabilities, obtained by using a fixed set of the model’s parameters, which are estimated through the maximum likelihood technique based on a learning period of about 32 years (1983–2015). According to the guidance proposed by the Collaboratory for the Study of Earthquake Predictability (CSEP), we also perform the N- and S-statistical tests to verify the reliability of the forecasts. Results show that the OEF system forecasts a number of events comparable to the observed one, and also captures quite well the spatial distribution of the real catalog with the exception of two target events that occurred in low seismicity regions.

show abstract

Section: Etes Modelmentioning

confidence: 99%

An Operational Earthquake Forecasting Experiment for Israel: Preliminary Results

et al. 2021

View full text Add to dashboard Cite

show abstract

“…where Mo Deficit is the cumulative moment deficit associated with the interseismic loading, Mo Seismic the cumulative seismic moment, and Mo aseismic the cumulative aseismic moment due to postseismic afterslip (and various slow slip events that occur during the interseismic and pre-seismic periods). Assuming that the frequency-magnitude distribution of megathrust earthquakes follows the Gutenberg-Richter (G-R) law on the long-term (Gutenberg and Richter, 1944):…”

Section: Seismic Moment Balance At the Scale Of The 1906 Colombia-ecuador Subduction Zonementioning

confidence: 99%

Seismic and Aseismic Cycle of the Ecuador–Colombia Subduction Zone

et al. 2021

View full text Add to dashboard Cite

The Colombia–Ecuador subduction zone is an exceptional natural laboratory to study the seismic cycle associated with large and great subduction earthquakes. Since the great 1906 Mw = 8.6 Colombia–Ecuador earthquake, four large Mw > 7.5 megathrust earthquakes occurred within the 1906 rupture area, releasing altogether a cumulative seismic moment of ∼35% of the 1906 seismic moment. We take advantage of newly released seismic catalogs and global positioning system (GPS) data at the scale of the Colombia–Ecuador subduction zone to balance the moment deficit that is building up on the megathrust interface during the interseismic period with the seismic and aseismic moments released by transient slip episodes. Assuming a steady-state interseismic loading, we found that the seismic moment released by the 2016 Mw = 7.8 Pedernales earthquake is about half of the moment deficit buildup since 1942, suggesting that the Pedernales segment was mature to host that seismic event and its postseismic afterslip. In the aftermath of the 2016 event, the asperities that broke in 1958 and 1979 both appears to be mature to host a large Mw > 7.5 earthquakes if they break in two individual seismic events, or an Mw∼7.8–8.0 earthquake if they break simultaneously. The analysis of our interseismic-coupling map suggests that the great 1906 Colombia–Ecuador earthquake could have ruptured a segment of 400 km-long bounded by two 80 km wide creeping segments that coincide with the entrance into the subduction of the Carnegie ridge in Ecuador and the Yaquina Graben in Colombia. These creeping segments share similar frictional properties and may both behave as strong seismic barriers able to stop ruptures associated with great events like in 1906. Smaller creeping segments are imaged within the 1906 rupture area and are located at the extremities of the large 1942, 1958, 1979, and 2016 seismic ruptures. Finally, assuming that the frequency–magnitude distribution of megathrust seismicity follows the Gutenberg–Richter law and considering that 50% of the transient slip on the megathrust is aseismic, we found that the maximum magnitude subduction earthquake that can affect this subduction zone has a moment magnitude equivalent to Mw ∼8.8 with a recurrence time of 1,400 years. No similar magnitude event has yet been observed in that region.

show abstract

“…The Gutenberg-Richter (G-R) law describes the magnitude-frequency relationship of earthquakes, which is lgN = a − bM [1,2]. In the formula, constant a reflects the seismicity of the region, and constant b indicates the relative ration of small to large earthquakes.…”

Section: Introductionmentioning

confidence: 99%

Assessing Earthquake Forecast Performance Based on b Value in Yunnan Province, China

Wang

Chang

Miao

et al. 2021

Entropy

View full text Add to dashboard Cite

Many studies have shown that b values tend to decrease prior to large earthquakes. To evaluate the forecast information in b value variations, we conduct a systematic assessment in Yunnan Province, China, where the seismicity is intense and moderate–large earthquakes occur frequently. The catalog in the past two decades is divided into four time periods (January 2000–December 2004, January 2005–December 2009, January 2010–December 2014, and January 2015–December 2019). The spatial b values are calculated for each 5-year span and then are used to forecast moderate-large earthquakes (M ≥ 5.0) in the subsequent period. As the fault systems in Yunnan Province are complex, to avoid possible biases in b value computation caused by different faulting regimes when using the grid search, the hierarchical space–time point-process models (HIST-PPM) proposed by Ogata are utilized to estimate spatial b values in this study. The forecast performance is tested by Molchan error diagram (MED) and the efficiency is quantified by probability gain (PG) and probability difference (PD). It is found that moderate–large earthquakes are more likely to occur in low b regions. The MED analysis shows that there is considerable precursory information in spatial b values and the forecast efficiency increases with magnitude in the Yunnan Province. These results suggest that the b value might be useful in middle- and long-term earthquake forecasts in the study area.

show abstract

Frequency of earthquakes in California*

Cited by 3,437 publications

References 1 publication

An Operational Earthquake Forecasting Experiment for Israel: Preliminary Results

An Operational Earthquake Forecasting Experiment for Israel: Preliminary Results

Seismic and Aseismic Cycle of the Ecuador–Colombia Subduction Zone

Assessing Earthquake Forecast Performance Based on b Value in Yunnan Province, China

Contact Info

Product

Resources

About