Stress transfer process in doublet events studied by numerical TREMOL simulations: Study case Ometepec 1982 Doublet.
Authors: de la Puente Josep , Monterrubio-Velasco Marisol , Rodríguez-Pérez Quetzalcoátl , Zúñiga Francisco Ramón , Rojas Otilio 
Published: March 2020

&lt;pre class=&quot;western&quot;&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;Earthquake doublets are a characteristic rupture &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;type&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt; defined as successive events with similar magnitude, &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;occurring&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt; wit&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;hin a short space-time window. Doublets appear to be a &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;characteristic feature for &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;regions of the world &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;such as Solomon islands, the Middle American Trench at Guerrero, or the Iranian plateau&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;. Previous studies found that a relatively homogeneous distribution of similar-size asperities may be responsible for the frequent occurrence of doublets in the Ometepec area at the Mexican subduction zone. The failure of one asperity may trigger another situated nearby due to stress transfer. However, the exact stress-transfer processes &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;among&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt; asperities are not well known. &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;In this way&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;, the research on seismic doublets is of great importance since it can contribute to a better understanding of earthquake triggering mechanisms &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;and &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt; regional subduction processes. On the 7th of June 1982, an earthquake doublet consisting of two events of Mw = 6.9 &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;that &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;occurred within five hours in the Ometepec area (Guerrero State, Me&amp;#769;xico), being one of the best documented earthquake doublet &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;cases ever recorded&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;. &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;I&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;n this &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;work, &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;we employ&lt;/span&gt;&lt;/span&gt; &lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;t&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;he &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;&lt;em&gt;sTochastic Rupture Earthquake MOdeL&lt;/em&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;, &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;TREMO&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;L&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt; code to study doublet phenomena by means of numerical simulations. &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;It is based on the &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;&lt;em&gt;Fiber Bundle model&lt;/em&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt; (FBM), &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;originally developed&lt;/span&gt;&lt;/span&gt; &lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;to&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt; describe rupture process&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;es&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt; in heterogeneous materials. &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;FBM&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt; has been &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;previously&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt; used to &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;characterize&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt; different earthquake rupture scenarios, such as singlets or aftershocks. &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;TREMOL&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt; analyze&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;s&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt; earthquake dynamics &lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;from a stochastic point of view, &lt;/span&gt;&lt;/span&gt; &lt;span&gt;where random distributions of load and asperity size along the fault surface, allow fitting observed seismicity. &lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt;Our results indicate that synthetic doublet earthquakes show transfer-load, and magnitude characteristics similar to those of the 1982 Ometepec study case. Moreover, we show the capabilities of TREMOL to capture a transition between the asperity model, and the barrier model. Our tests demonstrate that TREMOL is a powerful &lt;/span&gt;&lt;/span&gt;&lt;span&gt;and computationally efficient tool to study the complexity of&lt;/span&gt;&lt;span&gt;&lt;span lang=&quot;en-US&quot;&gt; earthquake ruptures. &lt;/span&gt;&lt;/span&gt;&lt;/pre&gt;