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World Organization of Volcanic Observatories

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1803
Equipo de Volcanologia y Geofísica Volcánica

Departamento de Volcanologia (1)
Museo Nacional de Ciencias Naturales CSIC
José Gutierrez Abascal 2
E-28006 Madrid
Spain

Instituto de Astronomia y Geodesia CSIC-UCM (2)
Faculdad de Ciencias Matematicas, UCM
Ciudad Universitaria
E-28040 Madrid
Spain

Centro Geofisico de Canarias (3)
c/La Marina, Edificio Multiple
E-38001 Santa Cruz de Tenerife
Spain
Telephone : (34) 91- 4111328             Telephone : (34) 91- 3944586    
Telefax : (34) 91- 5644740   Telefax :      
Director: Ramon Ortiz   Director: Ricardo Vieira Díaz    
Email : ramon@mncn.csic.es   Email : vieira@iagmat1.mat.ucm.es    

Website :

 www.mncn.csic.es/english/index1.html
  

Website :

 www.mat.ucm.es/deptos/iag/
    

Scientist in charge:

Ramon Ortiz - Geophysics (1)
Ricardo Vieira - Geodesy (2)
M. José Blanco - Seismology (3)
Vicente Araña - Volcanology (1)
Alicia Garcia - Volcanomagnetism (1)

The traditional concept of Volcanological Observatory is that of a group of people and instruments continuously monitoring the volcano activity. This, which can be justified for volcanoes of almost continuous activity or for those ones that due to their own characteristics are foreseen to go into eruption in a short time, is not easy to understand in areas such as the Canary Islands where the volcanic activity is very dispersed both in time and space. In that Archipelago, the eruptions that took place in the last thousand years have only been strictly monogenetic basaltic ones. The present volcanic activity in the Canary Islands should be considered moderate in probability of eruptions and very low in danger. In fact, work carried out (petrology, fluids geochemistry, geophysics) does not indicate any presence of magmatic chambers likely to produce eruptions of explosive characteristics in a central volcano.

In areas such as the Canarian Archipelago, surveillance of volcanic activity should be extended to the whole territory, outlining networks of little density but able to detect in any point the first appearing anomaly. These networks are complemented by periodical surveys of specifical character. These surveys cover a double objective: to monitor the volcanic activity "base line" and make operators familiar with field work as well as to try new techniques and equipments. In the case of an alarm, the needed instrumentations can be quickly spread over the area. This crisis instrumentation would be as dense as necessary and will come from all the research centers interested in the subject, either national ones or from other european countries related with the experience and with which we usually collaborate. The volcanological investigation carried out jointly between the different centers allows to optimize the available instrumentation and to develop the software needed to exchange and process.

The Equipo de Volcanologia y Geofísica Volcánica has been constituted to coordinate the joint performance of:

a. A group (Centro Geofisico de Canarias-IGN) with a solid and efficient framework and installations at the Canaries.

b. Interdisciplinary groups working in Volcanology Research in Canary Islands. These groups have portable intruments and can nucleate Task Force in volcanic crisis ocurrence at Canary Islands.

CHARACTERISTICS OF THE PRESENT VOLCANIC ACTIVITY (June 1995) IN THE CANARY ISLAND

a. Scattered character:

- in time (ten years periods to thousands of years)

- in space (hundreds of kilometers).

b. All eruptions from more than thousand years ago are basaltic ones.

c. There are no volcanic systems:

- in persistent activity

- with recent eruptions concentration

- with active magmatic chambers

- domes presently in evolution

d. Volcano monitoring results:

- Geophysical:

very little seismicity associated with volcanic systems.

- Geodesy:

there are no deformation effects in the caldera of Teide.

- Geochemical:

stability in the temperature and composition of every fluids issue.

Under these conditions, it is not possible to define an area showing a higher eruption probability in a medium term.

(*) With data from the IGN's Regional Seismic Network (Centro Geofísico de Canarias CGC/IGN), from Lanzarote Geodynamic Station (Cabildo Insular - Instituto de Astronomia y Geodesia IAG/CSIC-UCM) and periodic campaigns on microseismicity, gas geochemistry (Radon emissions control included), gravimetry, geomagnetism, geodesy are carried out by the Departamento of Volcanologia of Museo Nacional de Ciencias Naturales (MNCN/CSIC) and the Instituto de Astronomia y Geodesia (IAG/CSIC-UCM). The CGC/IAG start up from 1958. The MNCN and the IAG/CSIC-UCM deals with the Canarian active volcanism from 1970. The Geodinamical Station is in permanent operation from 1984 with 34 international instruments (Spain, China, Belgium, Luxembourg, Iceland, Rusia).

 

CANARY ISLAND VOLCANO SURVEILLANCE PROGRAM

1. PRESENT PERMANENT FACILITIES

a. Regional Seismic Network (CGC/IAG)

- 10 stations (Tenerife 5, La Palma, Hierro, Fuerteventura, Gran Canaria, Lanzarote)

- 1 seismic aray (Teide caldera) (CGC & MNCN/CSIC)

- 1 seismic array (Timanfaya Volcano, Lanzarote) (MNCN/CSIC).

Allowance to locate any event with magnitude 2.3 in any point of the Archipelago.

b. Geodesic and high accuracy levelling network (IAG/CSIC-UCM, CGC/IGN)

Following the islands communications ways in singular volcanic systems (Teide's caldera)

c. Magnetic Observatory and magnetic stations (CGC/IGN)

d. Geodynamic Station (IAG/CSIC-UCM)

Remote accessible by MODEM.

Instruments: Gravimeters (2), water-tube (4), mareograph (4), microthermometer (8), microbarograph (2), vertical pendulum (5), seismic station short period (2), seismic station broad band (1), horizontal pendulum (4), extensometer (2).

Objectives:

- Development and experimentation of new instruments and methods.

- Study of the transfer functions for the correct interpretation of detected anomalies.

- Study of the possible correlation existing between instrumental information and regional seismic and volcanic activity.

2. PORTABLE INSTRUMENTS (MNCN/CSIC & IAG/CSIC-UCM)

a. 8 portable 3 components seismic stations with continuous digital seismic recording (24 bits) and GPS time systems.

b. 32 channels seismic array (16 bits) with GPS time systems.

c. Gas sampling and analysis system.

d. EDM (two colours) and others geodetical instruments.

e. 4 Lacoste-Romberg gravimeters with electronic feed-back.

f. 4 Proton magnetometers and 2 flux gate magnetometers.

g. Magnetotelluric instruments (0.01 Hz-100 Hz)

3. PERIODICAL SURVEY

a. Geochemistry (MNCN/CSIC)

Analysis of gas emanations existing in fumaroles and soils.

Analysis of ground waters.

b. Thermometry of thermal anomalies (MNCN/CSIG).

c. Microseismicity of the latest eruption areas (CGC/IGN & MNCN/CSIC)

4. SPORADIC SURVEY

a. Gravimetry (IAG/CSIC-UCM & CGC/IGN)

b. Geomagnetism (MNCN/CSIC & CGC/IGN)

c. Resistivity (MNCN/CSIC)

d. Self-potential (MNCN/CSIC)

5. INFORMATION AND CIVIL EDUCATION PROGRAM

a. Casa de los Volcanes (Lanzarote) (MNCN/CSIC Cabildo Insular).

With exhibition rooms and specialized library. Audiovisual means. Publication service.

b. International Course on Volcanology and Volcano Geophysics. (MNCN/CSIC).

With special attention to active volcanism and physics of the volcanic process. Supported by IAVCEI, NESCO, AECI, ESF, ECGS.

c. Every year the team celebrates a workshop dedicated to instrumentation and data processing about Earth’s Science and special focus in volcanology.

 

Information updated June 2003

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