1. NAME: Nicaraguan Seismic Network, since 1992
The network had a forerunner in the years 1975-85.
2. STAFF
Dr. Wilfried Strauch
Director Técnico de Geofísica (Research Director
for Geophysics)
INETER Dirección General de Geofísica
Managua, Nicaragua
http://www.ineter.gob.ni/
email wil.gf@ineter.gob.ni
phone (505)2492761
fax (505)2491082
Network maintenance: Antonio Acosta, Martha Herrera, Alan Morales
Computer maintenance: Richard Blanco
Seismologists working in the 24-hours monitoring system: Antonio Acosta , Mario Bodán, Richard Blanco, Carlos Guzmán, Martha Herrera, Griselda Marroquín, Alejandro Morales, Allan Morales, Fabio Segura, Wilfried Strauch, Emilio Talavera, Virginia Tenorio, Manuel Traña
Daily and monthly revisions: Mario Bodan, Virginia Tenorio
Volcano-seismic monitoring: Virginia Tenorio, Emilio Talavera
Bulletins: Virginia Tenorio
3. GEOGRAPHICAL LOCATION:
Western Nicaragua 10 N - 13 N 85 W - 89 W
4. NETWORK CODE:
NIC
5. INSTITUTION(S):
Instituto Nicaraguense de Estudios Territoriales Managua Nicaragua Apdo 2110
Fax (505)2492761
6. STATIONS:
36 short period telemetric stations, 3 3-comp. sites, 1 digital broad band station, 20 digital strong motion stations
7. RECORDING:
Central recording of telemetric stations:
SEISLOG data logger, 64 channels, 50 Hz, 12 bit, triggered and continuous recording (main recording system) SEISLOG data logger, 32 channels, 50 Hz, 12 bit, triggered and continuous recording (backup recording system) SEISLOG data logger, 3 channels, 50 Hz, 24 bit, (3-comp. broad-band recording of Managua station) EARTHWORM data logger, 64 channels, 100 Hz, 12 bit, triggered and continuous (volcano monitoring)
Local recording of strong motion stations located in Managua and the main cities:
ETNA digital accelerographs, 50 Hz, 18 bit, triggered. Online access via INTERNET to ten of the stations.
Broad band station: near the city of Boaco, Quanterra datalogger, STS-2 seismometer, access via telephone line
8. DATA ANALYSIS:
Seismic monitoring is carried out both for
I. Tectono-seismic activity, and II. Volcano-seismic activity
I. Data processing of tectono-seismic events includes the following steps
1. Event detection and emission of an acoustic alert signal on the base of the data of the Nicaraguan Seismic Network 2. Access vía INTERNET of corresponding data from other Central American countries (if available) 3. Automatic location and magnitude estimation (5 minutes after occurrence) 4. revision of the automatic results by the seismologist on duty - within 10-30 minutes, for events between 7 AM and 11 PM, before 8 am for the events which occurred between 11 PM and 7 AM) - within 10-15 minutes after the event occurred, for any strong event. 5. In case of strong events: - transmission of fax and email messages with information about epicenter, depth, origin time, distance to Managua, and explanations about the causes of the event, to about 50 institutions in Nicaragua (Civil Defense, government, radio and TV stations, newspapers, news agencies, other institutions) - transmission of hypocenter and phase data to the seismic data centers in Costa Rica, Panama, Honduras, El Salvador, Guatemala 6. Daily revision of the results by an experienced seismologist 7. Monthly revisions and elaboration of the monthly bulletin, within the first week of the next month
II. Volcano-seismic activity
1. Automatic continuous determination and display of RSAM (for seismic station near the craters of active volcanoes) 2. Continuous counting of number of events per hour 3. Seismologist on duty monitors visually these parameters, checks the occurrence of seismic swarms near volcanoes 4. In case of important changes - seismologist on duty informs Civil Defense - alert messages to population, if volcanic activity confirmed - routine information message to population, in case of ongoing eruptions
9. DATA AVAILABILITY:
Web pages :
Near real time information
Epicenter map and list:
http://www.ineter.gob.ni/geofisica/sis/sis-act-nic-map.html
Helicorder type of seismograms of selected stations : http://www.ineter.gob.ni/geofisica/sis/dat/worm/Webicorder/Final/welcome.html
Spectrograms of selected stations:
http://www.ineter.gob.ni/geofisica/sis/dat/worm/Sgram/Final/index.html
seismological bulletins: http://www.ineter.gob.ni/geofisica/sis/bolsis/bolsis.html
seismology in Nicaragua: http://www.ineter.gob.ni/geofisica/sis/dep-sis.html
Regular printed publications ----------------------------
Monthly Bulletin "Sismos y Volcanes de Nicaragua" :
appears immediately after finishing the monthly revision. Distribution:
INETER, several agencies in Nicaragua, cooperating seismological
agencies in Central America, South America, Europe, USA. Contents:
Hypocenter lists and maps, macroseismic data, accounts on disastrous
events, information about the volcano-seismic activity, volcanic
eruptions, the development of the seismic network, short reports,
reports about ongoing projects.
Yearly catalogue: appears in the first months of the following year. Contents: similar as the monthly bulletins, resumes the most important activities in the year. Distribution: as the monthly bulletin
Phase data and waveforms ------------------------ can be obtained writing to: wil.gf@ineter.gob.ni
It is thought to implement automatic access to these data using a Webpage or AutoDRM.
A copy of all data is sent regularly to the Central American Seismic Data Center (CASC), recently at University of Costa Rica (UCR), San Jose, Costa Rica.
10. OTHER PRODUCTS:
Seismicity map of Nicaragua, Seismic Hazard study for Nicaragua and Managua Seismic Microzonation study for Managua Educational material for schools in Nicaragua
The Nicaraguan Seismic Network is the main information source of the Nicaraguan Disaster Reduction and Mitigation System, especially the Civil Defense Organization, on seismic and volcanic activity in Nicaragua and the Central American Region.
11. NEW OR PROPOSED DEVELOPMENTS:
During 2000-2001 the network will be densified in the area of Managua and expanded towards the Eastern part (Atlantic coast) of Nicaragua. The EARTHWORM recording system, which in the moment serves mainly for the volcano-seismic monitoring program, is thought to work also for the tectonic seismicity - in parallel to the existing SEISLOG systems. During 2000-2002 the on line and near real time processing capabilities of the network will be improved. Computer programs for the automatic determination of the seismic moment magnitude with broad band data will be installed. The team of seismologists on duty will be trained further on the fast and reliable processing of strong regional seismic events.
12. APPROXIMATE SIZE OF DATA SUBMISSION FOR CD-ROM
Less than 20 Mbyte of uncompressed hypocenter and phase data
13. ACKNOWLEDGEMENTS
The network is maintained with funding from the Nicaraguan government through the Instituto Nicaraguense de Estudios Territoriales, INETER.
Considerable scientific and technical contributions for the development of the network and training of personnel were obtained from Norwegian Seismic Array, NORSAR; University of Bergen, Norway; University of Geneva, Switzerland; Technical University Zurich, ETH, Switzerland; US Geological Survey, Volcano Disaster Assistance Program, VDAP; GeoForschungsZentrum Potsdam, GFZ, Germany;
Funding was obtained from Norwegian Development Agency, NORAD; Swiss Disaster Relief Agency; Swiss Development Agency, COSUDE; US Geological Survey, USGS; Swedish Development Agency; German Technical Cooperation, GTZ; Center for the Reduction of Natural Catastrophes in Central America, CEPREDENAC, Panama.