Global Seismographic Network
Programs L2 Landing Page
The Global Seismographic Network (GSN) is a permanent digital network of state-of-the-art seismological and geophysical sensors connected by a telecommunications network. The GSN provides, worldwide monitoring of the Earth, with over 150 modern seismic stations distributed globally.
Laboratory tests of three Z‐Land Fairfield Nodal 5‐Hz, three‐component sensors
We conduct a number of laboratory tests at the Albuquerque Seismological Laboratory to verify the self‐noise and fidelity in which 3 three‐component Fairfield Nodal Z‐Land, Generation 2, 5‐Hz sensors are able to record seismic signals. In addition to the incoherent self‐noise of the sensors, we estimate the sensitivity of the units in digital...Ringler, Adam; Anthony, Robert E.; Karplus, M.S; Holland, Austin; Wilson, David
The widespread influence of Great Lakes microseisms across the United States revealed by the 2014 polar vortex
During the winter of 2014, a weak polar vortex brought record cold temperatures to the north‐central (“Midwest”) United States, and the Great Lakes reached the highest extent of ice coverage (92.5%) since 1979. This event shut down the generation of seismic signals caused by wind‐driven wave action within the lakes (termed “lake microseisms”),...Anthony, Robert E.; Ringler, Adam; Wilson, David
Spatial and spectral interpolation of ground-motion intensity measure observations
Following a significant earthquake, ground‐motion observations are available for a limited set of locations and intensity measures (IMs). Typically, however, it is desirable to know the ground motions for additional IMs and at locations where observations are unavailable. Various interpolation methods are available, but because IMs or their...Worden, Charles; Thompson, Eric M.; Baker, Jack W.; Bradley, Brendon A.; Luco, Nicolas; Wald, David J.
Improvements in absolute seismometer sensitivity calibration using local earth gravity measurements
The ability to determine both absolute and relative seismic amplitudes is fundamentally limited by the accuracy and precision with which scientists are able to calibrate seismometer sensitivities and characterize their response. Currently, across the Global Seismic Network (GSN), errors in midband sensitivity exceed 3% at the 95% confidence...Anthony, Robert E.; Ringler, Adam; Wilson, David
Effects of thermal variability on broadband seismometers: Controlled experiments, observations, and implications
Isolating seismic instruments from temperature fluctuations is routine practice within the seismological community. However, the necessary degree of thermal stability required in broadband installations to avoid generating noise or compromising the fidelity in the seismic records is largely unknown and likely application dependent. To quantify the...Doody, Claire; Ringler, Adam; Anthony, Robert E.; Wilson, David; Holland, Austin; Hutt, Charles R.; Sandoval, Leo
Detection and characterization of pulses in broadband seismometers
Pulsing - caused either by mechanical or electrical glitches, or by microtilt local to a seismometer - can significantly compromise the long‐period noise performance of broadband seismometers. High‐fidelity long‐period recordings are needed for accurate calculation of quantities such as moment tensors, fault‐slip models, and normal‐mode...Wilson, David; Ringler, Adam; Hutt, Charles R.
Repeatability of testing a small broadband sensor in the Albuquerque Seismological Laboratory Underground Vault
Variability in seismic instrumentation performance plays a fundamental role in our ability to carry out experiments in observational seismology. Many such experiments rely on the assumed performance of various seismic sensors as well as on methods to isolate the sensors from nonseismic noise sources. We look at the repeatability of estimating the...Ringler, Adam; Holland, Austin; Wilson, David
Characterizing local variability in long‐period horizontal tilt noise
Horizontal seismic data are dominated by atmospherically induced tilt noise at long periods (i.e., 30 s and greater). Tilt noise limits our ability to use horizontal data for sensitive seismological studies such as observing free earth modes. To better understand the local spatial variability of long‐period horizontal noise, we observe horizontal...Rohde, M.D.; Ringler, Adam; Hutt, Charles R.; Wilson, David; Holland, Austin; Sandoval, L.D; Storm, Tyler
Broadband seismic noise attenuation versus depth at the Albuquerque Seismological Laboratory
Seismic noise induced by atmospheric processes such as wind and pressure changes can be a major contributor to the background noise observed in many seismograph stations, especially those installed at or near the surface. Cultural noise such as vehicle traffic or nearby buildings with air handling equipment also contributes to seismic background...Hutt, Charles R.; Ringler, Adam; Gee, Lind
PhasePApy: A robust pure Python package for automatic identification of seismic phases
We developed a Python phase identification package: the PhasePApy for earthquake data processing and near‐real‐time monitoring. The package takes advantage of the growing number of Python libraries including Obspy. All the data formats supported by Obspy can be supported within the PhasePApy. The PhasePApy has two subpackages: the PhasePicker and...Chen, Chen; Holland, Austin
Potential improvements in horizontal very broadband seismic data in the IRIS/USGS component of the Global Seismic Network
The Streckeisen STS‐1 has been the primary vault‐type seismometer used in the over‐150‐station Global Seismographic Network (GSN). This sensor has long been known for its outstanding vertical, very long‐period (e.g., >100 s period), and low‐noise performance, although the horizontal long‐period noise performance is less well...Ringler, Adam; Steim, J.M.; Zandt, T; Hutt, Charles R.; Wilson, David; Storm, Tyler
A quick SEED tutorial
Introduction A number of different government-funded seismic data centers offer free open-access data (e.g., U.S. Geological Survey, National Earthquake Information Center, the Incorporated Research Institutions for Seismology (IRIS), and Data Management System), which can be freely downloaded and shared among different members of the community (...Ringler, Adam; Evans, John R.
Although no one can reliably predict earthquakes, today’s technology is advanced enough to rapidly detect seismic waves as an earthquake begins, calculate the maximum expected shaking, and send alerts to surrounding areas before damage can occur. This technology is known as “earthquake early warning” (EEW).
While the number of large earthquakes fell to 12 in 2014, from 19 in 2013, several moderate temblors hit areas relatively new to seismicity, including Oklahoma and Kansas, according to the U.S. Geological Survey. Worldwide, 11 earthquakes reached magnitude 7.0-7.9 and one registered magnitude 8.2, in Iquique, Chile, on April 1.
Scientists from the U.S. Geological Survey and Virginia Tech will install a 20-station seismic network in the central Virginia area beginning Jan. 8. The new sensors – each about the size of a soda can – will provide information to help the researchers study the background seismicity in the area and any continuing aftershocks of the Aug. 23, 2011 earthquake near Louisa and Mineral, Va.