GEOLOGICAL SURVEY CIRCULAR 791 Seismograph Station Codes and Characteristics Seismograph Station Codes and Characteristics By Barbara B. Poppe, Debbi A. Naab, and John S. Derr G E 0 L 0 G I CAL 5 U R V E Y C I R C U LA R 791 1978 United States Department of the Interior CECIL D. ANDRUS, Secretary Geological Survey H. William Menard, Director Free on application to Branch of Distribution, U.S. Geological Survey, 1200 South fads Street, Arlington, VA 22202 CONTENTS Page Introduc,tion ........•..........................•............................ 1 Code assignment ••.•.•.•••. .•.••...••.•........•••....•.•••...•..•....••..••. 2 Description of tables ••••••••••••••••••••••••••••••••••••••••••••••••••••••• 2 Pub 1 i cat ions • • . • • • . • . • . • • . • • • • . • • . • • . • . • • . • • • • . • • • . • · • . · •• · • • • • 4 Glossary of abbreviations ••••••••••••••••••••••••••••••••••••••••••••••••••• 8 TABLES Table !.--Operating stations listed alphabetically by code •••••••••••••••••• 9 Table 2.--Closed stations listed alphabetically by code ••••••••••••••••••••• 92 Table 3.--Stations included in standard u.s. Geological Survey networks ••••• 127 Table 4.--Alternate names for stations •••••••••••••••••••••••••••••••••••••• 129 Table 5.--Countries having stations, listed by continent and island groups •• 131 Table 6.--LRSM stations, listed alphabetically by code •••••••••••••••••••••• 132 ILLUSTRATIONS Figure 1.--u.s. map showing the telemetered network recorded at NElS •••••••• 3 Figure 2.--World map showing the Worldwide Standardized Seismograph Network. 5 Figure 3.--World map showing the standard u.s. Geological Survey digital- recording stations................................................. 6 Cross index by country, region, and station code •••••••••••••••••••••••••••• 141 III Seismograph Station Codes and Characteristics By Barbara B. Poppe, Debbi A. Naab, and John S. Derr INTRODUCTION The seismological community will soon be entering its second 100 years of activity as it marks the centennial of a handful of seismograph stations. In the 100 years since the first few installations began timed recording of earth-shaking, the number of stations has ballooned into the thousands, which has led to the necessity for indexing and cataloging these stations. The stations contained in this publication represent the large portion of the world's installations that are operated in a cooperative spirit; they are stations that have exchanged data with one or both of the largest data centers for teleseismic data: the NElS (National Earthquake Information Service) and the ISC (International Seismological Centre). Hoping that this cooperation will continue, we urge all operators to check their station coordinates and inform us of corrections or additions. The earliest catalogs, such as a 1908 publication of the Bureau Central de !'Association Internationale de Sismologie, listed all the stations operating in the world at the time; nearly 200 existed then, referred to by name and country. By 1931, in a second edition of the Bulletin of the National Research Council's List of Seismological Stations of the World, McComb and West listed 350 stations operating worldwide. By 1960, the USC&GS (u.s. Coast and Geodetic Survey) had adapted the station data for use on the computer and thus assigned three-letter codes to the stations from which they had received data. This informal code system became recognized as a valuable tool and began being used outside the USC&GS. Consequently, the USC&GS published its list of station codes in 1962, followed by several rev1s1ons and addenda. The task of assigning codes was carried to the USGS (U.S. Geological Survey) in 1972, when the responsibility for Government seismological activities was reassigned to the USGS. This publication is an update of the 1974 NElS publication "Seismograph Station Abbreviations and Coordinates" by Pamela A. Covington. The NElS now maintains this list as an integral part of its work which is, among other things, to rapidly locate all teleseismic events that are accurately recorded by at least five well-distributed stations. Currently, about 6,000 earthquakes are located each year. Particular emphasis is given to u.s. 1 earthquakes, which are located rapidly with the aid of a telemetry network of about 60 stations recorded in Golden, Colo. (See fig. 1.) A standby service is always in operation so that any major event in the United States or the world can be located within 2 to 3 hours of its occurrence; this service makes use of the telemetered network and any telephone or telegraph information that is received. Any arrival-time data that are received at the NElS are used for locating events as long as proper identification of a station is established. The information contained in this publication for each station comprises the essential. details required. CODE ASSIGNMENT As stated above, only stations that have contributed data to the NElS or ISC have had codes assigned. Three- or four-letter codes are assigned using the following ground rules: the first letter should be the first letter of the name of the neareBt town or geographically identifiable place (for instance, Golden, Colo., station should start with a G), and the last letter can indicate the country or region •. There are several code restrictions. Telegraphic transmission of data requires that certain codes be forbidden; a list of these codes is checked before any code is assigned. Stations that have been moved more than 1 km are assigned new codes. In some microseismic networks, locations are accurate to much less than 1 km and, in these instances, new codes can be assigned, if requested. For teleseismic work, however, 1-km resolution is adequate. All four-letter codes ending in 0 have been reserved for SRO (Seismic Research Observatory) and ASRO (Abbreviated Seismic Research Observatory) stations; this coding alerts the computer to automatically identify and interpret trace amplitudes when they are received. In order to make use of data as soon as it is received, a code is reserved when preliminary information about a new station is communicated to the NElS. If no data are registered under a reserved code within a year or two of assignment, the code is deleted, thus allowing it to be assigned to another station. ~fuen data are received for a reserved station, the data are immediately identifiable and the station is changed to an "open" status. Once a station is opened, its code will remain in the files permanently and will never be reassigned to another station. When an open station is discontinued, the code status changes to "closed" but remains a permanent entry. It is hard to ascertain when a station closes, because mere lack of receipt of data is not enough evidence for closing a station. The station operators should relay information to NElS when a station's status is closed. DESCRIPTION OF TABLES Tables 1 and 2 are both listings of codes, station names, and locations; table 1 lists open stations and table 2 lists closed stations. Names listed in parentheses are "alternate 2 j~ c------T~------~------~~------~~------~"ru-·------~'uro~-------~'ur'--------~~ro-______ _,~4~--------~,u~--------~;o~"-------;~<~"------~'~r"------~7;4"________ 7~0~"------~6~6-'----~ 3F w ' \ V'~ \, r ,~ \ 0 MILES 500 Figure 1.--The telemetered network recorded at NElS. Triangles represent stations; station codes, which are listed in table 1, are noted alongside. names," which are cross-referenced in table 4. The region is listed in areas where subdivisions are useful, as in Japan, U.S.S.R., and the U.S.A. The country generally is the sovereignty of the area, but does not always reflect possession (Easter Island is not listed under Chile). Preceding the tables is a glossary of abbreviations used throughout the publication. Owing to the nature of our computer storage and printing capabilities, diacritical marks could not be used. Latitude and Longitude are listed first in degrees, minutes, and seconds, then as degrees and decimal degrees. Either form reflects the accuracy of the coordinates as reported to us and is not meant to imply uniform accuracy. The elevation of the instrument is in meters. For borehole installations, the elevation is that of the seismometer in the borehole. If the elevation is given as 0, it may be 0, nearly 0, or unknown. However, some unknown elevations were estimated to be 400. Standardized networks that are administered by the USGS are noted under the heading "Station networks." Table 3 is a quick reference for all stations belonging to one of the standard u.s. Geological Survey networks. These standard networks are plotted in figures 2 and 3. Table 4 is a cross-reference of alternate names; it is meant to help find a station code that often does not start with the same first letter as the alternate station name. Thus, the alternate name Marguerite Bay, Antarctica, can be used to find its code, ANC. Table 5 lists, by continents and general regions, countries or island groups that operate at least one seismograph station; the classification "Islands in the Pacific and Indian Oceans" groups together all the islands in this region, regarQless of sovereignty. Table 6 is a list of LRSM (Long Range Seismic Measurement) stations, organized by ARPA (Advance Research Projects Agency). These station were installed to monitor nuclear tests and most operated during a very limited time frame. These codes are not cross indexed. The cross index alphabetically lists all codes under their country and region. Thus, at a