Were Global M ≥8:3 Earthquake Time Intervals Random between 1900 and 2011?

The pattern of great earthquakes during the past ∼100 yr raises questions whether large earthquake occurrence is linked across global distances, or whether temporal clustering can be attributed to random chance. Great-earthquake frequency during the past decade in particular has engendered media speculation of heightened global hazard. We therefore examine interevent distributions of Earth's largest earth- quakes at one-year resolution, and calculate how compatible they are with a random- in-time Poisson process. We show, using synthetic catalogs, that the probability of any specific global interevent distribution happening is low, and that short-term clusters are the least repeatable features of a Poisson process. We examine the real catalog and find, just as expected from synthetic catalogs, that the least probable M ≥8:3 earth- quake intervals during the past 111 yr were the shortest ( t< 1 yr) if a Poisson process is active (mean rate of 3.2%). When we study an M ≥8:3 catalog with locally trig- gered events removed, we find a higher mean rate of 9.5% for 0-1 yr intervals, com- parable to the value (11.1%) obtained for simulated catalogs drawn from random- in-time exponential distributions. We emphasize short interevent times here because they are the most obvious and have led to speculation about physical links among global earthquakes. We also find that comparison of the whole 111-yr observed M ≥8:3 interevent distribution (including long quiescent periods) to a Poisson process is not significantly different than the same comparison made with synthetic catalogs. We therefore find no evidence that global great-earthquake occurrence is not a ran- dom-in-time Poisson process.

[1]  E. Geist,et al.  Assessing historical rate changes in global tsunami occurrence , 2011 .

[2]  John McCloskey,et al.  Seismology: Earthquake risk on the Sunda trench , 2005, Nature.

[3]  Andrew J. Michael,et al.  Random variability explains apparent global clustering of large earthquakes , 2011 .

[4]  Tom Parsons,et al.  Global Omori law decay of triggered earthquakes: Large aftershocks outside the classical aftershock zone , 2002 .

[5]  P. M. Shearer,et al.  Global risk of big earthquakes has not recently increased , 2011, Proceedings of the National Academy of Sciences.

[6]  D. Perkins,et al.  Evidence for a global seismic-moment release sequence , 2005 .

[7]  Y. Ogata.  Space-Time Point-Process Models for Earthquake Occurrences , 1998 .

[8]  G. King,et al.  STATIC STRESS CHANGES AND THE TRIGGERING OF EARTHQUAKES , 1994 .

[9]  E. R. Engdahl,et al.  41 - Global Seismicity: 1900–1999 , 2002 .

[10]  Alvaro Corral.  Long-term clustering, scaling, and universality in the temporal occurrence of earthquakes. , 2004, Physical review letters.

[11]  P. Bodin,et al.  Earthquake nucleation by transient deformations caused by the M = 7.9 Denali, Alaska, earthquake , 2004, Nature.

[12]  Christopher H. Scholz,et al.  Off-fault aftershock clusters caused by shear stress increase? , 1981 .

[13]  F. Omori,et al.  On the after-shocks of earthquakes , 1894 .

[14]  M. Bartlett.  On the Theoretical Specification and Sampling Properties of Autocorrelated Time‐Series , 1946 .

[15]  Ross S. Stein,et al.  The 1979 Homestead Valley Earthquake Sequence, California: Control of Aftershocks and Postseismic Deformation , 1983 .

[16]  D. Hill.  Dynamic Stresses, Coulomb Failure, and Remote Triggering , 2008 .

[17]  A. Freed.  EARTHQUAKE TRIGGERING BY STATIC, DYNAMIC, AND POSTSEISMIC STRESS TRANSFER , 2005 .

[18]  W. Ellsworth,et al.  Seismicity Remotely Triggered by the Magnitude 7.3 Landers, California, Earthquake , 1993, Science.

[19]  R. Bürgmann,et al.  Stress and Seismicity Changes on the Sunda Megathrust Preceding the 2007 Mw 8.4 Earthquake , 2011 .

[20]  K. Yamashina.  Induced earthquakes in the Izu peninsula by the Izu-Hanto-Oki earthquake of 1974, Japan , 1978 .

[21]  Alessandro Vespignani,et al.  Velocity and hierarchical spread of epidemic outbreaks in scale-free networks. , 2003, Physical review letters.

[22]  J. Chéry,et al.  Postseismic stress transfer explains time clustering of large earthquakes in Mongolia , 2001 .

[23]  F. Pollitz,et al.  Viscosity of oceanic asthenosphere inferred from remote triggering of earthquakes , 1998, Science.

[24]  T. Parsons,et al.  Absence of remotely triggered large earthquakes beyond the mainshock region , 2011 .

[25]  Frank Scherbaum,et al.  Estimating Background Activity Based on Interevent-Time Distribution , 2006 .

[26]  J. Lees,et al.  Seismicity, Earthquakes and Structure Along the Alaska‐Aleutian and Kamchatka‐Kurile Subduction Zones: A Review , 2013 .