Analysis of the spatial distribution between successive earthquakes

Area of Science:

• Geophysics
• Seismology
• Statistical Physics

Background:

• Earthquake occurrence patterns are crucial for seismic hazard assessment.
• Understanding the spatial and temporal relationships between earthquakes is a key challenge in seismology.
• Previous models often assumed relationships between main shock magnitude and aftershock zone scaling.

Purpose of the Study:

• To investigate the statistical properties of spatial distances between consecutive earthquakes in Southern California.
• To determine if these spatial statistics are influenced by factors like magnitude thresholds, spatial distribution, or temporal ordering.
• To test the validity of existing theories, such as aftershock zone scaling, against observed earthquake data.

Main Methods:

• Analysis of earthquake catalogs for Southern California.
• Statistical analysis of spatial distances between successive seismic events.
• Examination of scale-free statistics and finite size scaling.
• Correlation analysis between spatial distances, waiting times, and temporal ordering.

Main Results:

• Spatial distances between earthquakes exhibit scale-free statistics with a critical exponent delta ≈ 0.6.
• Statistics are independent of magnitude thresholds in complete catalogs.
• Earthquake statistics are strongly dependent on the temporal sequence of events, not spatial epicenter distribution.
• Spatial distance and waiting time between earthquakes are uncorrelated.
• Findings contradict theories of aftershock zone scaling with main shock magnitude.

Conclusions:

• Earthquake spatial-temporal dynamics in Southern California display scale-invariant properties.
• The temporal ordering of events is a dominant factor in earthquake statistics, challenging purely geometric models.
• Observed patterns necessitate a re-evaluation of current earthquake rupture and aftershock models.