Geology Reports⌕ Search
Home/Archive/USGS

USGS · 70234245

Near real-time monitoring of seismic events and status of portable digital recorders using satellite telemetry

R.J. Mueller·Meei-You Lee·M.J.S. Johnston·Roger D. Borcherdt·G. Glassmoyer·S. Silverman
View original source ↗Export metadata ↓

Abstract

Near real-time monitoring of seismic events and status of portable 16-bit digital recorders has been established for arrays near Parkfield, Mammoth Lakes, and San Francisco, California. This monitoring system provides near real-time seismic event identification (rough location and magnitude) and a cost-effective means to maintain arrays at near 100% operational level. Principal objectives in the design of this system have been portability and low-cost telemetry. The system has been developed to use portable digital seismic recorders ( GEOS —General Earthquake Observation System) and portable data collection platforms ( DCP 's) for the Geostationary Operational Environmental Satellite (GEOS) telemetry system. Data are transferred asynchronously from the GEOS seismic system through a microprocessor-controlled interface every 10 min. The interface stores, determines priority, converts, and synchronously transfers these data to a Sutron Corp. model 8004 DCP for transmission through the GEOS satellite telemetry system. Event parameters include trigger time, peak amplitude, time of peak amplitude, and event duration. Instrument configuration parameters, transmitted at system start-up time and every 24 hr, include recording parameters, trigger parameters, GEOS software version, clock reference, and location parameter. Instrument status includes battery voltage, number of events, and percentage of tape usage. These data are transmitted as appropriate to the U.S. Geological Survey satellite downlink and computers located in Menlo Park, California, where they are processed and displayed.

Explore related subjects

Bulletin of the Seismological Society of AmericaArticle

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

R.J. Mueller, Meei-You Lee, M.J.S. Johnston, Roger D. Borcherdt, G. Glassmoyer, S. Silverman. 1995. Near real-time monitoring of seismic events and status of portable digital recorders using satellite telemetry. https://doi.org/10.1785/bssa0850020640

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2026

Re-evaluation of shaking, dynamic strain, and the source of the 1886 Charleston, South Carolina, earthquake

As the largest historical event in the eastern United States, the 1886 Charleston, South Carolina, earthquake, plays a prominent role in our nation’s seismological and human history and an outsized role in our probabilistic ground‐motion hazard estimates, affecting building codes, insurance rates, and geophysical monitoring. Thus, constraining the characteristics of the 1886 earthquake source, as well as the nature of its shaking distribution and impacts to the extent possible, is essential. Given its vintage, however, societal, geological, and geophysical datasets are limited compared with those used in modern seismological analyses. Because of these limitations, some characteristics of the rupture model are fundamentally nonunique. Still, by re‐evaluating all available data, I can constrain several key aspects of this earthquake. I show that several interpretations in recent analyses are inconsistent regarding the inferred source; shaking; ground failure; and, particularly, railway impacts. Importantly, I have shown that although dynamic strain caused the ground failure that led to track deformation, without the intermediate liquefaction step, dynamic strain alone was unlikely to be the source of rail deformation, contrary to earlier studies. Had earlier pronouncements that dynamic strain is a real concern for bending railways held true, there would be serious ramifications for railway engineering as well as for other above‐ and below‐ground linear infrastructure.

South Carolina↗
USGS2026

ETAS-positive: Extracting unbiased epidemic-type aftershock models from incomplete earthquake catalogs

Earthquake catalogs are inherently incomplete, and short-term fluctuations in catalog completeness can strongly bias estimates of seismicity parameters. Here, we extend the positive statistics framework recently introduced for estimating Gutenberg–Richter a and b values to the Epidemic-Type Aftershock Sequence (ETAS) model. The approach focuses on complete magnitude–time intervals defined by pairs of earthquakes in which the second event is larger than the first. Comprehensive synthetic tests demonstrate that the proposed ETAS + method retrieves nearly unbiased parameter estimates even from highly incomplete catalogs, whereas parameters obtained using classical estimation approaches are strongly biased. Application to Southern California reveals a similar trend, with the productivity scaling parameter α approaching the b value, consistent with self-similar earthquake triggering within estimation uncertainties. Owing to its robustness against catalog incompleteness and computational efficiency, the ETAS + method provides a powerful new tool for seismicity analysis and earthquake forecasting.

California↗