Development of a New Approach to Earthquake Prediction: Load/Unload Response Ratio (LURR) Theory

Abstract

Abstract-The seismogenic process is nonlinear and irreversible so that the response to loading is different from unloading. This difference reflects the damage of a loaded material. Based on this insight, a new parameter-load/unload response ratio (LURR) was proposed to measure quantitatively the proximity to rock failure and earthquake more than ten years ago. In the present paper, we review the fundamental concept of LURR, the validation of LURR with experimental and numerical simulation, the retrospective examination of LURR with new cases in different tectonic settings (California, USA, and Kanto region, Japan), the statistics of earthquake prediction in terms of LURR theory and the random distribution of LURR under Poisson's model. Finally we discuss LURR as a parameter to judge the closeness degree to SOC state of the system and the measurement of tidal triggering earthquake.The Load/Unload Response Ratio (LURR) theory was first proposed in 1984 (YIN, 1987). Subsequently, a series of advances were made (YIN and

A probabilistic approach for earthquake potential evaluation based on the load/unload response ratio method

“…where '+' and '−' refer to the loading and unloading processes, and X is the response rate [20,21]. Suppose that P and R are, respectively, the load and response of the nonlinear system, then…”

“…(2) To designate the earthquake occurrence ranges: If the value of a random variable is less than 0.5, the corresponding 'earthquake' is assumed to take place during the loading process and vice versa. Assuming that c is an LURR anomaly computed using the LURR method [21], the probability for 0<LURR<c can be determined with the stochastic distribution of LURR (as the shadowed area indicated in Figure 2), and may suggest the degree of anomaly of the LURR. On the other hand, according to the LURR method, only when c is greater than 1, tidal stress triggering of earthquakes should occur.…”

“…The load/unload response ratio (LURR) method is devised based on such a strategy [20]. The application of the method typically involves evaluating the Earth tideinduced Coulomb failure stress change on faults, differentiating its loading and unloading periods, determining the Benioff strain releases of earthquakes during both periods from earthquake data input, and calculating the ratio between the two Benioff strain releases [21,22]. When a system is stable, its response to loading is usually about the same as its response to unloading; whereas when the system is in an unstable state, the response to loading is usually much higher than the response to unloading.…”

“…When a system is stable, its response to loading is usually about the same as its response to unloading; whereas when the system is in an unstable state, the response to loading is usually much higher than the response to unloading. The method has been applied to a large number of earthquake prediction practices [20][21][22][23][24]. Results show that prior to most of the large earthquakes studied, anomalously high LURR values were observed months to years ahead [20,21].…”

“…The method has been applied to a large number of earthquake prediction practices [20][21][22][23][24]. Results show that prior to most of the large earthquakes studied, anomalously high LURR values were observed months to years ahead [20,21]. Based on the LURR studies, we propose a probabilistic approach to assess the confidence level of LURR anomalies for earthquake occurrence.…”