Wuestefeld, Andreas; Spica, Zack J.; Aderhold, Kasey; Huang, Hsin H.; Ma, Kuo F.; Lai, Voon H.; Miller, Meghan; Urmantseva, Lena; Zapf, Daniel; Bowden, Daniel C.; Edme, Pascal; Kiers, Tjeerd; Rinaldi, Antonio P.; Tuinstra, Katinka; Jestin, Camille; Diaz-Meza, Sergio; Jousset, Philippe; Wollin, Christopher; Ugalde, Arantza; Barajas, Sandra R.; Gaite, Beatriz; Currenti, Gilda; Prestifilippo, Michele; Araki, Eiichiro; Tonegawa, Takashi; De Ridder, Sjoerd; Nowacki, Andy; Lindner, Fabian; Schoenball, Martin; Wetter, Christoph; Zhu, Hong H.; Baird, Alan F.; Rorstadbotnen, Robin A.; Ajo-Franklin, Jonathan; Ma, Yuanyuan; Abbott, Robert A.; Hodgkinson, Kathleen; Porritt, Robert W.; Stanciu, Adrian; Podrasky, Agatha; Hill, David; Biondi, Biondo; Yuan, Siyuan; Bin LuoBin; Nikitin, Sergei; Morten, Jan P.; Dumitru, Vlad A.; Lienhart, Werner; Cunningham, Erin; Wang, Herbert
During February 2023, a total of 32 individual DAS systems acted jointly as a global seismic monitoring network. The aim of this Global DAS Month campaign was to coordinate a diverse network of organizations, instruments, and file formats in order to gain knowledge and move toward the next generation of earthquake monitoring networks. During this campaign, 156 earthquakes of magnitude 5 or larger were reported by the USGS and contributors shared data for 60 min after each event’s origin time. Participating systems represent a variety of manufacturers, a range of recording parameters, and varying cable emplacement settings (e.g., shallow burial, borehole, subaqueous, dark fiber). Monitored cable lengths vary between 152 and 120129 m, with channel spacing between 1 and 49 m. The data has a total size of 6.8 TB, and is available for free download. Organizing and executing the Global DAS Month has produced a unique dataset for further exploration and highlighted areas of further development for the seismological community to address.
Characterizing the shallow structure of the Rock Valley region of the Nevada National Security Site is a critical component of the Rock Valley Direct Comparison project. Geophysical data of the region is needed for operational decisions, to constrain geologic models used for simulation, and to facilitate the analysis of future explosive source data. Local measurements of gravity are a key piece of geophysical information that helps to resolve the underlying geologic composition, fault structure, and density characteristics, yet, in the Rock Valley region these measurements are sparse on the scale of the testbed. In this report, we present the details of a recent gravity data acquisition survey designed to collect a dense dataset in the region of interest that complements the existing gravity work but greatly enhances our resolution. This dataset will be integrated with a complementary Los Alamos National Laboratory gravity collection and combined with the existing seismic data in a joint inversion. These measurements were conducted over two weeks with a portable gravimeter and high-resolution GPS and include repeat measurements at a USGS base station as well as reoccupation of gravity sites in the regional dataset. This collection of over 100 new dense gravity measurements will facilitate refinement of the existing Geologic Framework Model and directly complement newly acquired dense seismic data, ultimately improving the project’s ability to investigate the direct comparison of shallow earthquake and explosive sources.