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At least 55 records · Page 3Linked to original sources
USGS1919

Hawaiian Volcano Observatory bulletins - 1919

The Hawaiian Volcano Observatory (HVO) Bulletin series was an informal publication issued between the years 1913 to 1929. Individual issues contain information on volcanic and earthquake activity, volcano research, and volcano monitoring in Hawaii, and issues often included photographs, sketches, and data plots. Information on volcanic activity at other locations is also occasionally included. The Bulletin series was published by HVO through the Hawaiian Volcano Research Association. Weekly Bulletins (initially called Reports) were issued between June 28, 1913, and July 1, 1914. Bulletins were issued monthly after July 1, 1914, though they were still named Weekly Bulletins until January 1919. Starting with the February 1919 issue, the Bulletins were named Monthly Bulletins, and they continued to be issued monthly until the series ceased in July 1929. During a single year, 1915, Seismometric Bulletins were also issued quarterly. These four issues contain summaries of seismic observations recorded by the then-nascent Whitney Laboratory of Seismology, located underground in a vault near the summit of Kīlauea. Two of the bulletins are misnumbered: • April 1916 volume IV no. 4 incorrectly says April 1915 volume III no. 4 • September 1916 volume IV no. 9 incorrectly says September 1916 volume VI no. 9

Hawaii↗
USGS1920

Hawaiian Volcano Observatory bulletins - 1920

The Hawaiian Volcano Observatory (HVO) Bulletin series was an informal publication issued between the years 1913 to 1929. Individual issues contain information on volcanic and earthquake activity, volcano research, and volcano monitoring in Hawaii, and issues often included photographs, sketches, and data plots. Information on volcanic activity at other locations is also occasionally included. The Bulletin series was published by HVO through the Hawaiian Volcano Research Association. Weekly Bulletins (initially called Reports) were issued between June 28, 1913, and July 1, 1914. Bulletins were issued monthly after July 1, 1914, though they were still named Weekly Bulletins until January 1919. Starting with the February 1919 issue, the Bulletins were named Monthly Bulletins, and they continued to be issued monthly until the series ceased in July 1929. During a single year, 1915, Seismometric Bulletins were also issued quarterly. These four issues contain summaries of seismic observations recorded by the then-nascent Whitney Laboratory of Seismology, located underground in a vault near the summit of Kīlauea. Two of the bulletins are misnumbered: • April 1916 volume IV no. 4 incorrectly says April 1915 volume III no. 4 • September 1916 volume IV no. 9 incorrectly says September 1916 volume VI no. 9

Hawaii↗
USGS1921

Hawaiian Volcano Observatory bulletins - 1921

The Hawaiian Volcano Observatory (HVO) Bulletin series was an informal publication issued between the years 1913 to 1929. Individual issues contain information on volcanic and earthquake activity, volcano research, and volcano monitoring in Hawaii, and issues often included photographs, sketches, and data plots. Information on volcanic activity at other locations is also occasionally included. The Bulletin series was published by HVO through the Hawaiian Volcano Research Association. Weekly Bulletins (initially called Reports) were issued between June 28, 1913, and July 1, 1914. Bulletins were issued monthly after July 1, 1914, though they were still named Weekly Bulletins until January 1919. Starting with the February 1919 issue, the Bulletins were named Monthly Bulletins, and they continued to be issued monthly until the series ceased in July 1929. During a single year, 1915, Seismometric Bulletins were also issued quarterly. These four issues contain summaries of seismic observations recorded by the then-nascent Whitney Laboratory of Seismology, located underground in a vault near the summit of Kīlauea. Two of the bulletins are misnumbered: • April 1916 volume IV no. 4 incorrectly says April 1915 volume III no. 4 • September 1916 volume IV no. 9 incorrectly says September 1916 volume VI no. 9

Hawaii↗
USGS1922

Hawaiian Volcano Observatory bulletins - 1922

The Hawaiian Volcano Observatory (HVO) Bulletin series was an informal publication issued between the years 1913 to 1929. Individual issues contain information on volcanic and earthquake activity, volcano research, and volcano monitoring in Hawaii, and issues often included photographs, sketches, and data plots. Information on volcanic activity at other locations is also occasionally included. The Bulletin series was published by HVO through the Hawaiian Volcano Research Association. Weekly Bulletins (initially called Reports) were issued between June 28, 1913, and July 1, 1914. Bulletins were issued monthly after July 1, 1914, though they were still named Weekly Bulletins until January 1919. Starting with the February 1919 issue, the Bulletins were named Monthly Bulletins, and they continued to be issued monthly until the series ceased in July 1929. During a single year, 1915, Seismometric Bulletins were also issued quarterly. These four issues contain summaries of seismic observations recorded by the then-nascent Whitney Laboratory of Seismology, located underground in a vault near the summit of Kīlauea. Two of the bulletins are misnumbered: • April 1916 volume IV no. 4 incorrectly says April 1915 volume III no. 4 • September 1916 volume IV no. 9 incorrectly says September 1916 volume VI no. 9

Hawaii↗
USGS1923

Hawaiian Volcano Observatory bulletins - 1923

The Hawaiian Volcano Observatory (HVO) Bulletin series was an informal publication issued between the years 1913 to 1929. Individual issues contain information on volcanic and earthquake activity, volcano research, and volcano monitoring in Hawaii, and issues often included photographs, sketches, and data plots. Information on volcanic activity at other locations is also occasionally included. The Bulletin series was published by HVO through the Hawaiian Volcano Research Association. Weekly Bulletins (initially called Reports) were issued between June 28, 1913, and July 1, 1914. Bulletins were issued monthly after July 1, 1914, though they were still named Weekly Bulletins until January 1919. Starting with the February 1919 issue, the Bulletins were named Monthly Bulletins, and they continued to be issued monthly until the series ceased in July 1929. During a single year, 1915, Seismometric Bulletins were also issued quarterly. These four issues contain summaries of seismic observations recorded by the then-nascent Whitney Laboratory of Seismology, located underground in a vault near the summit of Kīlauea. Two of the bulletins are misnumbered: • April 1916 volume IV no. 4 incorrectly says April 1915 volume III no. 4 • September 1916 volume IV no. 9 incorrectly says September 1916 volume VI no. 9

Hawaii↗
USGS1924

Hawaiian Volcano Observatory bulletins - 1924

The Hawaiian Volcano Observatory (HVO) Bulletin series was an informal publication issued between the years 1913 to 1929. Individual issues contain information on volcanic and earthquake activity, volcano research, and volcano monitoring in Hawaii, and issues often included photographs, sketches, and data plots. Information on volcanic activity at other locations is also occasionally included. The Bulletin series was published by HVO through the Hawaiian Volcano Research Association. Weekly Bulletins (initially called Reports) were issued between June 28, 1913, and July 1, 1914. Bulletins were issued monthly after July 1, 1914, though they were still named Weekly Bulletins until January 1919. Starting with the February 1919 issue, the Bulletins were named Monthly Bulletins, and they continued to be issued monthly until the series ceased in July 1929. During a single year, 1915, Seismometric Bulletins were also issued quarterly. These four issues contain summaries of seismic observations recorded by the then-nascent Whitney Laboratory of Seismology, located underground in a vault near the summit of Kīlauea. Two of the bulletins are misnumbered: • April 1916 volume IV no. 4 incorrectly says April 1915 volume III no. 4 • September 1916 volume IV no. 9 incorrectly says September 1916 volume VI no. 9

Hawaii↗
USGS1925

Hawaiian Volcano Observatory bulletins - 1925

The Hawaiian Volcano Observatory (HVO) Bulletin series was an informal publication issued between the years 1913 to 1929. Individual issues contain information on volcanic and earthquake activity, volcano research, and volcano monitoring in Hawaii, and issues often included photographs, sketches, and data plots. Information on volcanic activity at other locations is also occasionally included. The Bulletin series was published by HVO through the Hawaiian Volcano Research Association. Weekly Bulletins (initially called Reports) were issued between June 28, 1913, and July 1, 1914. Bulletins were issued monthly after July 1, 1914, though they were still named Weekly Bulletins until January 1919. Starting with the February 1919 issue, the Bulletins were named Monthly Bulletins, and they continued to be issued monthly until the series ceased in July 1929. During a single year, 1915, Seismometric Bulletins were also issued quarterly. These four issues contain summaries of seismic observations recorded by the then-nascent Whitney Laboratory of Seismology, located underground in a vault near the summit of Kīlauea. Two of the bulletins are misnumbered: • April 1916 volume IV no. 4 incorrectly says April 1915 volume III no. 4 • September 1916 volume IV no. 9 incorrectly says September 1916 volume VI no. 9

Hawaii↗
USGS1926

Hawaiian Volcano Observatory bulletins - 1926

The Hawaiian Volcano Observatory (HVO) Bulletin series was an informal publication issued between the years 1913 to 1929. Individual issues contain information on volcanic and earthquake activity, volcano research, and volcano monitoring in Hawaii, and issues often included photographs, sketches, and data plots. Information on volcanic activity at other locations is also occasionally included. The Bulletin series was published by HVO through the Hawaiian Volcano Research Association. Weekly Bulletins (initially called Reports) were issued between June 28, 1913, and July 1, 1914. Bulletins were issued monthly after July 1, 1914, though they were still named Weekly Bulletins until January 1919. Starting with the February 1919 issue, the Bulletins were named Monthly Bulletins, and they continued to be issued monthly until the series ceased in July 1929. During a single year, 1915, Seismometric Bulletins were also issued quarterly. These four issues contain summaries of seismic observations recorded by the then-nascent Whitney Laboratory of Seismology, located underground in a vault near the summit of Kīlauea. Two of the bulletins are misnumbered: • April 1916 volume IV no. 4 incorrectly says April 1915 volume III no. 4 • September 1916 volume IV no. 9 incorrectly says September 1916 volume VI no. 9

Hawaii↗
USGS1927

Hawaiian Volcano Observatory bulletins - 1927

The Hawaiian Volcano Observatory (HVO) Bulletin series was an informal publication issued between the years 1913 to 1929. Individual issues contain information on volcanic and earthquake activity, volcano research, and volcano monitoring in Hawaii, and issues often included photographs, sketches, and data plots. Information on volcanic activity at other locations is also occasionally included. The Bulletin series was published by HVO through the Hawaiian Volcano Research Association. Weekly Bulletins (initially called Reports) were issued between June 28, 1913, and July 1, 1914. Bulletins were issued monthly after July 1, 1914, though they were still named Weekly Bulletins until January 1919. Starting with the February 1919 issue, the Bulletins were named Monthly Bulletins, and they continued to be issued monthly until the series ceased in July 1929. During a single year, 1915, Seismometric Bulletins were also issued quarterly. These four issues contain summaries of seismic observations recorded by the then-nascent Whitney Laboratory of Seismology, located underground in a vault near the summit of Kīlauea. Two of the bulletins are misnumbered: • April 1916 volume IV no. 4 incorrectly says April 1915 volume III no. 4 • September 1916 volume IV no. 9 incorrectly says September 1916 volume VI no. 9

Hawaii↗
USGS1928

Hawaiian Volcano Observatory bulletins - 1928

The Hawaiian Volcano Observatory (HVO) Bulletin series was an informal publication issued between the years 1913 to 1929. Individual issues contain information on volcanic and earthquake activity, volcano research, and volcano monitoring in Hawaii, and issues often included photographs, sketches, and data plots. Information on volcanic activity at other locations is also occasionally included. The Bulletin series was published by HVO through the Hawaiian Volcano Research Association. Weekly Bulletins (initially called Reports) were issued between June 28, 1913, and July 1, 1914. Bulletins were issued monthly after July 1, 1914, though they were still named Weekly Bulletins until January 1919. Starting with the February 1919 issue, the Bulletins were named Monthly Bulletins, and they continued to be issued monthly until the series ceased in July 1929. During a single year, 1915, Seismometric Bulletins were also issued quarterly. These four issues contain summaries of seismic observations recorded by the then-nascent Whitney Laboratory of Seismology, located underground in a vault near the summit of Kīlauea. Two of the bulletins are misnumbered: • April 1916 volume IV no. 4 incorrectly says April 1915 volume III no. 4 • September 1916 volume IV no. 9 incorrectly says September 1916 volume VI no. 9

Hawaii↗
USGS1929

Hawaiian Volcano Observatory bulletins - 1929

The Hawaiian Volcano Observatory (HVO) Bulletin series was an informal publication issued between the years 1913 to 1929. Individual issues contain information on volcanic and earthquake activity, volcano research, and volcano monitoring in Hawaii, and issues often included photographs, sketches, and data plots. Information on volcanic activity at other locations is also occasionally included. The Bulletin series was published by HVO through the Hawaiian Volcano Research Association. Weekly Bulletins (initially called Reports) were issued between June 28, 1913, and July 1, 1914. Bulletins were issued monthly after July 1, 1914, though they were still named Weekly Bulletins until January 1919. Starting with the February 1919 issue, the Bulletins were named Monthly Bulletins, and they continued to be issued monthly until the series ceased in July 1929. During a single year, 1915, Seismometric Bulletins were also issued quarterly. These four issues contain summaries of seismic observations recorded by the then-nascent Whitney Laboratory of Seismology, located underground in a vault near the summit of Kīlauea. Two of the bulletins are misnumbered: • April 1916 volume IV no. 4 incorrectly says April 1915 volume III no. 4 • September 1916 volume IV no. 9 incorrectly says September 1916 volume VI no. 9

Hawaii↗
USGS1915

Hawaiian Volcano Observatory seismometric bulletins - 1915

The Hawaiian Volcano Observatory (HVO) Bulletin series was an informal publication issued between the years 1913 to 1929. Individual issues contain information on volcanic and earthquake activity, volcano research, and volcano monitoring in Hawaii, and issues often included photographs, sketches, and data plots. Information on volcanic activity at other locations is also occasionally included. The Bulletin series was published by HVO through the Hawaiian Volcano Research Association. Weekly Bulletins (initially called Reports) were issued between June 28, 1913, and July 1, 1914. Bulletins were issued monthly after July 1, 1914, though they were still named Weekly Bulletins until January 1919. Starting with the February 1919 issue, the Bulletins were named Monthly Bulletins, and they continued to be issued monthly until the series ceased in July 1929. During a single year, 1915, Seismometric Bulletins were also issued quarterly. These four issues contain summaries of seismic observations recorded by the then-nascent Whitney Laboratory of Seismology, located underground in a vault near the summit of Kīlauea. Two of the bulletins are misnumbered: • April 1916 volume IV no. 4 incorrectly says April 1915 volume III no. 4 • September 1916 volume IV no. 9 incorrectly says September 1916 volume VI no. 9

Hawaii↗
USGS2022

On the documentation, independence, and stability of widely used seismological data products

Earthquake scientists have traditionally relied on relatively small data sets recorded on small numbers of instruments. With advances in both instrumentation and computational resources, the big-data era, including an established norm of open data-sharing, allows seismologists to explore important issues using data volumes that would have been unimaginable in earlier decades. Alongside with these developments, the community has moved towards routine production of interpreted data products such as seismic moment tensor catalogs that have provided an additional boon to earthquake science. As these products have become increasingly familiar and useful, it is important to bear in mind that they are not data, but rather interpreted data products. As such, they differ from data in ways that can be important, but not always appreciated. Important - and sometimes surprising - issues can arise if methodology is not fully described, data from multiple sources are included, or data products are not versioned (time-stamped). The line between data and data products is sometimes blurred, leading to an underappreciation of issues that affect data products. This note illustrates examples from two widely used data products: moment tensor catalogs and Did You Feel It? (DYFI) macroseismic intensity values. These examples show that increasing a data product’s documentation, independence, and stability can make it even more useful. To ensure the reproducibility of studies using data products, time-stamped products should be preserved, for example as electronic supplements to published papers, or, ideally, a more permanent repository.

Frontiers in Earth Science↗
USGS2005

An evaluation of the strong ground motion recorded during the May 1, 2003 Bingol Turkey, earthquake

An important record of ground motion from a M 6.4 earthquake occurring on May 1, 2003, at epicentral and fault distances of about 12 and 9 km, respectively, was obtained at a station near the city of Bingöl, Turkey. The maximum peak ground values of 0.55g and 36 cm/s are among the largest ground-motion amplitudes recorded in Turkey. From simulations and comparisons with ground motions from other earthquakes of comparable magnitude, we conclude that the ground motion over a range of frequencies is unusually high. Site response may be responsible for the elevated ground motion, as suggested from analysis of numerous aftershock recordings from the same station. The mainshock motions have some interesting seismological features, including ramps between the P- and S-wave that are probably due to near- and intermediate-field elastic motions and strong polarisation oriented at about 39 degrees to the fault (and therefore not in the fault-normal direction). Simulations of motions from an extended rupture explain these features. The N10E component shows a high-amplitude spectral acceleration at a period of 0.15 seconds resulting in a site specific design spectrum that significantly overestimates the actual strength and displacement demands of the record. The pulse signal in the N10E component affects the inelastic spectral displacement and increases the inelastic displacement demand with respect to elastic demand for very long periods.

Journal of Earthquake Engineering↗
USGS2015

Self-noise models of five commercial strong-motion accelerometers

Strong‐motion accelerometers provide onscale seismic recordings during moderate‐to‐large ground motions (e.g., up to tens of m/s 2 peak). Such instruments have played a fundamental role in improving our understanding of earthquake source physics (Bock etal. , 2011), earthquake engineering (Youd et al. , 2004), and regional seismology (Zollo et al. , 2010). Although strong‐motion accelerometers tend to have higher noise levels than high‐quality broadband velocity seismometers, their higher clip‐levels provide linear recordings at near‐field sites even for the largest of events where a collocated broadband sensor would no longer be able to provide onscale recordings (Clinton and Heaton, 2002). Recently, the seismological community has begun to make use of strong‐motion accelerometer data even in the absence of large ground motions (e.g., Tibuleac et al. , 2011). The noise floor of the instruments often limits the usefulness of strong‐motion accelerometer data in such studies, because it obscures first arrivals or can make the traces dominated by noise. When a strong‐motion accelerometer is deployed in a quiet setting, the noise floors of the digitizer and the accelerometer tend to dominate the other noise sources (Cauzzi and Clinton, 2013). This situation is unlike that using broadband sensors, in which site conditions are typically the largest contributing source of noise in seismic data, especially at long periods (Wilson et al. , 2002). With the widespread deployment of strong‐motion accelerometers recorded on high resolution digitizers, it is now possible to get continuous high‐rate acceleration data in which the digitizer noise is not the dominant noise source (Cauzzi and Clinton, 2013). To better characterize the noise of a number of commonly deployed accelerometers in a standardized way, we conducted noise measurements on five different models of strong‐motion accelerometers. Our study was limited to traditional accelerometers (Fig. 1) and is in no way exhaustive.

Seismological Research Letters↗
USGS2008

Location of the Green Canyon (Offshore Southern Louisiana) Seismic Event of February 10, 2006

We calculated an epicenter for the Offshore Southern Louisiana seismic event of February 10, 2006 (the 'Green Canyon event') that was adopted as the preferred epicenter for the event by the USGS/NEIC. The event is held at a focal depth of 5 km; the focal depth could not be reliably calculated but was most likely between 1 km and 15 km beneath sea level. The epicenter was calculated with a radially symmetric global Earth model similar to that routinely used at the USGS/NEIC for all earthquakes worldwide. The location was calculated using P-waves recorded by seismographic stations from which the USGS/NEIC routinely obtains seismological data, plus data from two seismic exploration arrays, the Atlantis ocean-bottom node array, operated by BP in partnership with BHP Billiton Limited, and the CGG Green Canyon phase VIII multi-client towed-streamer survey. The preferred epicenter is approximately 26 km north of an epicenter earlier published by the USGS/NEIC, which was obtained without benefit of the seismic exploration arrays. We estimate that the preferred epicenter is accurate to within 15 km. We selected the preferred epicenter from a suite of trial calculations that attempted to fit arrival times of seismic energy associated with the Green Canyon event and that explored the effect of errors in the velocity model used to calculate the preferred epicenter. The various trials were helpful in confirming the approximate correctness of the preferred epicenter and in assessing the accuracy of the preferred epicenter, but none of the trial calculations, including that of the preferred epicenter, was able to reconcile arrival-time observations and assumed velocity model as well as is typical for the vast majority of earthquakes in and near the continental United States. We believe that remaining misfits between the preferred solution and the observations reflect errors in interpreted arrival times of emergent seismic phases that are due partly to a temporally extended source-time function and partly to failure of our travel-time model to account for the extremely complicated velocity structure of the sedimentary section in which the event occurred.

Open-File Report↗
USGS1977

Catalog of earthquakes in the Santa Barbara Channel area for the period January 1, 1972 to December 31, 1973

The Santa Barbara Channel region forms the western most area of the Transverse Ranges, and is one of the most seismically active areas in the State of California. Instrumentally recorded earthquakes throughout southern California have been reported by the Seismological Laboratory of the California Institute of Technology (CALTECH) since 1932. Earthquake data for the period 1934 to 1963 were analyzed by Allen and others (1965) and related to regional geologic structures in southern California. Sylvester and others (1970) discussed the earthquake swarm that occurred in the Santa Barbara channel during the period from June 26 to August 3, 1968 with respect to the seismic history of the channel. The U. S. Geological Survey (USGS) (Vedder and others, 1969a) prepared a report on the geology, petroleum development, and seismicity of the Santa Barbara Channel region subsequent to an offshore oil-well blowout in the Dos Cuadras Offshore oil field. In that report, Hamilton and others (1969) reviewed the regional seismicity and its possible effects on the region. They noted that the existing seismic network precluded identification of individual active faults within the channel. A network of seismograph stations was established in late 1969 by the U. S. Geological Survey to monitor earthquakes in and around the Santa Barbara Channel. The purpose of this network is to provide data to gain insight into the tectonic and physical processes responsible for the generation of damaging earthquakes in the Santa Barbara Channel region. Lee and Vedder, (1973) reported the earthquakes located by this network for the period from January 1, 1970 to December 31, 1971, and showed that the earthquake activity appears to be spatially related to recognized faults in the region. This report contains a catalog of earthquakes in the Santa Barbara Channel region for the period from January 1, 1972 to December 31, 1973. It is prepared in a manner similar to that of the catalog contained in Lee and Vedder (1973) for the preceding two year period. These catalogs contain the basic study of seismicity in the Santa Barbara Channel region. The data contained in these catalogs provides a foundation for further study of the seismicity in tectonics of the Santa Barbara Channel region.

California↗
USGS1982

Design concepts for a Global Telemetered Seismograph Network

This study represents a first step in developing an integrated, real-time global seismic data acquisition system a Global Telemetered Seismograph Network (GTSN). The principal objective of the GTSN will be to acquire reliable, high-quality, real-time seismic data for rapid location and analysis of seismic events. A secondary, but important, objective of the GTSN is to augment the existing off-line seismic data base available for research. The deployment of the GTSN will involve a variety of interrelated activities development of the data acquisition and receiving equipment, establishment of satellite and terrestrial communication links, site selection and preparation, training of station personnel, equipment installation, and establishment of support facilities. It is a complex program and the development of a sound management plan will be essential. The purpose of this study is not to fix design goals or dictate avenues of approach but to develop working concepts that may be used as a framework for program planning. The international exchange of seismic data has been an important factor in the progress that has been made during the past two decades in our understanding of earthquakes and global tectonics. The seismic data base available for analysis and research is derived principally from the Global Seismograph Network (GSN), which is funded and managed by the U.S. Geological Survey (USGS). The GSN comprises some 120 seismograph stations located in more than 60 countries of the world. Established during the 1960 s with the installation of the World-Wide Standardized Seismograph Network (WWSSN) , the GSN has been augmented in recent years by the installation of more advanced data systems, such as the Seismic Research Observatories (SRO), the modified High-Gain LongPeriod (ASRO) seismographs, and the digital WWSSN (DWWSSN). The SRO, ASRO, and DWWSSN stations have the common, distinctive feature of digital data recording, so they are known collectively as the Global Digital Seismograph Network (GDSN). The fundamental objective in operating the GSN is to create and update a seismic data base that is accessible without restrictions to organizations and research scientists throughout the world. The USGS provides cooperating stations with instrumentation, training, and continuing support, including supplies and on-site maintenance. In return, the host organization operates the equipment and sends the recorded data to the USGS. Analog data (seismograms) are microfilmed and about four million copies are requested annually by researchers. Digital data, which are recorded on magnetic tape, are organized by the USGS Albuquerque Seismological Laboratory (ASL) into networkday tapes and copies of the day tapes are furnished to data users through national and regional data centers. After copying, original data are returned to the stations and used for local research. Most of the stations in the GSN also provide the USGS with seismic readings « phase arrival times and amplitudes scaled from the seismograms. These readings are transmitted on a daily or biweekly basis via commercial or diplomatic communication channels. They are used by the USGS National Earthquake Information Service (NEIS) to determine the location and magnitude of earthquakes occurring throughout the world. The results are published monthly in bulletins that are distributed to the participating stations and virtually all scientific organizations that are involved in seismological studies. It is a much-valued service that provides a current, updated catalog of seismic activity on a global scale. The NEIS also has the responsibility for rapid reporting of large and potentially destructive earthquakes. The NEIS issues news bulletins as soon as possible after the occurrence of magnitude 6.5 or greater earthquakes (magnitude 5 or greater in the conterminous United States). The news bulletins are sent to disaster relief, public safety, and other interested organizations. Tsunami warnings issued to countries bordering the Pacific Ocean are based initially on earthquake location and magnitude data. Rapid reporting of earthquakes requires real-time waveform data or readings. Currently, signals are being telemetered from more than thirty stations in the United States to the NEIS, which is located in Golden, Colorado. An extension of the telemetry network to other countries will provide the seismological community with a significantly improved means of monitoring earthquake activity in real time; it will lower the response time for determining the location and magnitude of potentially destructive or tsunamigenic earthquakes and it will provide more timely information that may be needed by governments to respond promptly.

Open-File Report↗