Natural Time, Nowcasting and the Physics of Earthquakes: Estimation of Seismic Risk to Global Megacities

Rundle, John B.; Luginbuhl, Molly; Giguere, Alexis; Turcotte, Donald L.

doi:10.1007/978-3-319-92297-3_10

Cited by 15 publications

(23 citation statements)

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“…We have shown in companion papers (Rundle et al, ) that the nowcasting method is generally not very sensitive to the choice of large spatial region defining the histogram, leading to a standard error of approximately ±10%. However, the method is strongly sensitive to issues of catalog completeness (Rundle et al, ).…”

Section: Discussionmentioning

confidence: 89%

“…Nowcasting refers to the use of proxy data to estimate the current dynamical state of a driven complex system such as earthquakes, neural networks, or the financial markets (Rundle et al, ). In previous papers (Rundle et al, ; Rundle et al, ), a method to nowcast earthquakes has been presented based on the natural time count of small earthquakes after the last large earthquake in a defined, seismically active geographic region. Natural time has been discussed extensively in Varotsos et al (, , ), Sarlis et al (, ), Vallianatos et al (), and Holliday et al ().…”

Section: Nowcastingmentioning

confidence: 99%

“…The (green) vertical bars in Figure represent the numbers of 6 ≤ M < 7.9 earthquakes between the M ≥ 7.9 great earthquakes that occurred worldwide since 1950. Small earthquake data from years prior to 1950 are not complete at the M ≥ 6 level (Rundle et al, ). The red curve monotonically ascending from lower left to upper right is the CDF corresponding to the histogram.…”

Section: Datamentioning

confidence: 99%

“…In Table , the EPS values are based on the sum of self‐information of the small earthquakes since the last great earthquake. Note that small earthquake counts for great earthquakes prior to 1950 are based on estimates whose accuracy is unknown (Rundle et al, ), a subject for future research.…”

Section: Magnitude Information Entropymentioning

confidence: 99%

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Global Seismic Nowcasting With Shannon Information Entropy

Rundle

Giguere

Turcotte

et al. 2019

Earth and Space Science

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Seismic nowcasting uses counts of small earthquakes as proxy data to estimate the current dynamical state of an earthquake fault system . The result is an earthquake potential score that characterizes the current state of progress of a defined geographic region through its nominal earthquake “cycle.” The count of small earthquakes since the last large earthquake is the natural time that has elapsed since the last large earthquake (Varotsos et al., 2006, https://doi.org/10.1103/PhysRevE.74.021123 ). In addition to natural time, earthquake sequences can also be analyzed using Shannon information entropy (“information”), an idea that was pioneered by Shannon (1948, https://doi.org/10.1002/j.1538‐7305.1948.tb01338.x ). As a first step to add seismic information entropy into the nowcasting method, we incorporate magnitude information into the natural time counts by using event self‐information. We find in this first application of seismic information entropy that the earthquake potential score values are similar to the values using only natural time. However, other characteristics of earthquake sequences, including the interevent time intervals, or the departure of higher magnitude events from the magnitude‐frequency scaling line, may contain additional information.

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Section: Discussionmentioning

confidence: 89%

Section: Nowcastingmentioning

confidence: 99%

Section: Datamentioning

confidence: 99%

Section: Magnitude Information Entropymentioning

confidence: 99%

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Global Seismic Nowcasting With Shannon Information Entropy

Rundle

Giguere

Turcotte

et al. 2019

Earth and Space Science

Self Cite

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“…This assumption seems reasonable in light of the ergodic dynamics in the statistical physics of seismicity, in which the statistics of smaller regions over longer times are considered to be similar to the statistics of broader regions over large spatial domains and longer periods (Tiampo et al, 2003;Holliday et al, 2016). Under this set up, the nowcasting method describes the seismic progression of a region in terms of earthquake potential score (EPS) measured through the cumulative probability for the current event counts (Rundle et al, 2016(Rundle et al, , 2018Pasari, 2019 (Monnier et al, 1995, Katili, 1978. The convergence zone of this trijunction accommodates a composite domain of accretionary complexes, micro-continental fragments, melange terrains, island arcs and ophiolites (Hall, 2012).…”

Section: Introductionmentioning

confidence: 99%

Nowcasting Earthquakes in Sulawesi Island, Indonesia

Pasari¹,

Simanjuntak

Sharma³

2020

Preprint

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Large devastating events such as earthquakes often display frequency-magnitude statistics that exhibit power-law distribution. In this study, we implement a new method of nowcasting (Rundle et al. 2016) to evaluate the current state of earthquake hazards in the seismic prone Sulawesi province, Indonesia. The nowcasting technique considers statistical behavior of small event counts, known as natural times, to infer the seismic progression of large earthquake cycles in a defined region. To develop natural time statistics in the Sulawesi Island, we employ four probability models, namely exponential, exponentiated exponential, gamma, and Weibull distribution. Statistical inference of natural times reveals that (i) exponential distribution has the best representation to the observed data; (ii) estimated nowcast scores (%) corresponding to M≥6.5 events for 21 cities are Bau-bau (41), Bitung (70), Bone (44), Buton (39), Donggala (63), Gorontalo (49), Kendari (27), Kolaka (30), Luwuk (56), Makassar (52), Mamuju (58), Manado (70), Morowali (37), Palopo (34), Palu (62), Pare-pare (82), Polewali (61), Poso (42), Taliabu (55), Toli-toli (58), and Watampone (55); and (iii) the results are broadly consistent to the changes of magnitude threshold and area of local regions. Therefore, the present nowcasting analysis, similar to the traditional earthquake hazard assessment techniques, offers a simple yet versatile metric to the scientists, engineers and policymakers to examine the current state of earthquake hazards in the thickly populated Sulawesi Island.

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China Seismic Experimental Site: Seismicity, Ergodicity and Nowcasting Earthquakes

Zhang

2022

China Seismic Experimental Site

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Natural Time, Nowcasting and the Physics of Earthquakes: Estimation of Seismic Risk to Global Megacities

Cited by 15 publications

References 0 publications

Global Seismic Nowcasting With Shannon Information Entropy

Global Seismic Nowcasting With Shannon Information Entropy

Nowcasting Earthquakes in Sulawesi Island, Indonesia

China Seismic Experimental Site: Seismicity, Ergodicity and Nowcasting Earthquakes

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