The Sept. 9, 2017 Chiapas, Mexico (M=8.1 ) and the Sept. 19 Puebla, Mexico (M=7.1) earthquakes occurred along a subduction zone, where the Cocos Plate ocean plate subducts beneath the continental North American Plate along the Middle American Trench. The second earthquake occurred in a much ight density population, and thus has dramatically impacted structures Although one might consider this event to be expected (large to giant earthquakes occur along subduction zones), initial results from the United Stated Geological Survey (USGS) show that these earthquake were unusual: they both did not occur along the plate interface. Instead, both earthquakes occurred within the subducting oceanic plate and both showed normal faulting, not the typical thrust event that would occur along a typical subduction zone. Furthermore, they were distant from each other, longer than two fault lengths, which is the distance at which static triggering forces tend to be very small, suggesting no link between the two. Thus, many questions remain about these earthquakes, including: 1) will this earthquake load the upper plate and possibly trigger an equal or larger earthquake on the plate interface? Is this the result of plate bending? Do the aftershocks migrate to the locked zone in the subduction zone? Did the earthquake rupture into the mantle? To address some of these questions, we propose to immediately deploy 10 broadband seismometers near the epicenters to record aftershocks for 6 months, and 50 nodes owned by UTEP. Although offshore, the epicentral region of the Chiapas can be monitored effectively by an onshore deployment due to the geographical attributes of the region. UTEP is uniquely qualified for executing the deployment, as we have built collaborations with colleagues at UNAM and UAJC in Juarez Mexico, plus the disaster agency of Mexico, Centro Nacional de Prevencion de Desastres (CENPRED). Furthermore, UTEP can field seismic instrumentation immediately, including state-of-the-art instruments that have yet to be deployed for an aftershock study, and the team has experience with large field deployments in remote regions in the world.