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Canaries – Cape Verde link to improve volcano monitoring 22 February 2010

Posted by admin in Atlantic, Canary Islands, Cape Verde Islands, volcano monitoring.
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The Canary Islands and the Cape Verde Islands are volcanic archipelagoes off the Atlantic coast of Africa: the Canaries constitute a territory of Spain, while the Cape Verde islands are a former Portuguese colony which is now an independent republic. Both are volcanically active, and volcano monitoring is a priority for both island groups.

The Instituto Tecnológico y de Energías Renovables (ITER) of Tenerife is involved in an extensive programme aimed at strengthening volcano monitoring in Cape Verde, reports Canarias 24 Horas. In collaboration with the Laboratorio de Engenharia de Cabo Verde (LEC), the Department of Science and Technology of the Universidade de Cabo Verde (UNICV) and the Cape Verde Serviço Nacional de Protecção Civil (SNPC), ITER has been providing training and technical resources to enhance volcano monitoring and hazard mitigation in Cape Verde. Particular programmes under way include the strengthening of local capacities for geochemical volcano monitoring, the measurement of volcanic gas emissions on São Vicente and Fogo islands, and the measurement of thermal energy release associated with gas emissions at Pico do Fogo, which has been the focus of recent volcanic activity in the Cape Verde Islands.

News
El ITER realiza una misión vulcanológica en Cabo Verde – Canarias24horas.com, 20 February 2010

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Gran Canaria volcanic hazards newly mapped 19 January 2010

Posted by admin in Gran Canaria, Spain.
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Mapa de riesgos volcánicos en Gran Canaria 2010

Researchers have compiled a comprehensive study of volcanic activity on the island of Gran Canaria from 11,000 years ago to the present day and used the data to produce a new hazard map of Gran Canaria (see above), indicating the areas of potentially greatest volcanic risk in the future. The findings are published in the Journal of Quaternary Research (full reference below).

Alejandro Rodríguez-González of the Universidad de Las Palmas de Gran Canaria, lead author of the study, explains:

We have identified 24 volcanic eruptions that have occurred over the last 11,000 years on Gran Canaria. We know that the volcanism was concentrated in the northern area of the island and produced small monogenetic strombolian cones (eruptions of little violence, emitting lava and pyroclasts) and, occasionally, phreatomagmatic calderas (expulsion of ash).

The research involved advanced Digital Terrain Modelling which revealed geomorphological changes produced by volcanic activity and the precise mapping of individual units of volcanic activity and their products. Combined with geochemical and stratigraphic data this enabled a detailed picture of the unfolding of volcanic activity on the island during the Holocene.

Not only does the study indicate that the areas at highest risk of future volcanic activity lie in the densely-populated north of the island, it also reveals that the intervals between periods of active volcanism are becoming shorter and the eruptions are becoming more voluminous and explosive:

The new findings highlight that during the Holocene there were three clusters of volcanic activity ‘separated by four periods of inactivity’. The earliest occurred over 10,000 years ago and consisted of a single eruption in El Draguillo, to the east of the island. The other eruptions occurred between 5,700 and 6,000 years ago, and between 1,900 and 3,200 years ago … the researchers explain that currently ‘the number of eruptive centres is increasing and the periods of volcanic inactivity are becoming shorter’. In the same way, they also warn that over the past 11,000 years ‘the amount of magma emitted and the explosiveness of the eruptions have been increasing’.

Ironically, however, the researchers note that damage to the island’s ecosystem may restrict the impact of future volcanic activity. The deforestation of Gran Canaria and the over-exploitation of limited water resources has left the island very dry, reducing the chances of water interacting with magma to produce explosive activity. The next eruption in Gran Canaria, which may be in ‘200-300 years’, is expected to be a strombolian event: quiet, non-explosive, with no casualties expected.

  • Rodríguez-González, Alejandro; Fernández-Turiel, José L.; Pérez-Torrado, Francisco J.; Hansen, Alex; Aulinas, Meritxell; Carracedo, Juan C.; Gimeno, Domingo; Guillou, Hervé; Paris, Raphael; Paterne, Martine. ‘The Holocene volcanic history of Gran Canaria island: implications for volcanic hazards’ Journal of Quaternary Science, vol. 24, no. 7 (October 2009), pp. 697-709. DOI: 10.1002/jqs.1294 (abstract).

UPDATE. A translation into English of the SINC (Servicio de Información y Noticias Científicas) news release is available at EurekAlert: Volcanic hazard map produced for island of Gran Canaria.

[Found via: Actualidad Volcánica de Canarias.]

News
Presentan un mapa de peligrosidad volcánica de la isla de Gran Canaria – Servicio de Información y Noticias Científicas, 18 January 2010
Un volcán despertará en Gran Canaria dentro de 200 años – Público.es, 19 January 2010
Presentan un mapa de peligrosidad volcánica de la isla de Gran Canaria – Actualidad Volcánica de Canarias, 19 January 2010
Volcanic hazard map produced for island of Gran Canaria – EurekAlert, 19 January 2010

Information
Global Volcanism Program: Gran Canaria – summary information for Gran Canaria (1803-04-)
Actualidad Volcánica de Canarias – news and information about Canary Islands volcanoes and earthquakes
Canary Islands volcanoes and volcanics – information from the Cascades Volcano Observatory

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