SM2.2Earthquake source processes: source parameter scaling relations, and outstanding issues
|Co-Conveners: Grzegorz Kwiatek , Joachim Ritter
One of the major questions in seismology is whether the physics of fault rupture is the same for large and small earthquakes. Namely, the question arises as to whether the source dimensions of a MW 7 earthquake are simply a scaled version of a MW -4 event. As small earthquakes are far more numerous than their larger counterparts, their abundance makes them easier to observe and study. Additionally, induced seismicity and laboratory seismicity provide opportunities to study small events under partially controlled conditions. Because of the abundance of small events, understanding whether earthquakes are self-similar down to very small ruptures is of practical importance for estimating hazard for natural earthquakes. If scaling relations for static and dynamic parameters of earthquakes are known, then an extrapolation of such values will help us to more accurately estimate expected values for larger, more devastating events.
Studies of earthquake scaling relations involve analysis of the Gutenberg-Richter distribution as well as comparisons of static and dynamic source parameters such as seismic moment, source radius, duration, and radiated seismic energy. Understanding the relationship of both the static and dynamic parameters with earthquake size is essential to understanding the self-similarity of earthquakes. In spite of increased station coverage in recent years, observations of parameter scaling relationships vary widely. As an example, many studies report static stress and apparent stress estimations at individual sites which often vary over a couple orders of magnitude between studies. Some of the variance in observations may result from differing geological or tectonic settings, however, in some cases, it may also result from the chosen method of data analysis and attenuation correction, particularly for smaller events.
This session aims to further the understanding of earthquake scaling relationships over a wide range of magnitudes, down to the laboratory scale. It investigates whether variations in parameter scaling are regionally dependent. It explores whether observed differences in scaling relations are real, and if so, what physical mechanisms might account for such differences.
We invite the people working on seismic source parameters and scaling relations of earthquakes from the nano- to giga-scale. We welcome contributions examining natural seismicity, induced seismicity, and laboratory seismicity from rock physics experiments.