Exhibition: The Canary Islands, Volcanoes in the Ocean
Las Palmas, 22 November 2002
Volcanoes are open vents in Earth’s crust through which melted materials emerge from the interior. These physical phenomena have sparked enormous interest and curiosity in man, who has often lived in fear of them. Nonetheless, volcanoes are the beginnings of islands and archipelagos -on many occasions they are the refuge of unique ecosystems- and spectacular landscapes. This is the case of the Canary Islands.
Organised by Fundació ”la Caixa” and the Council of Education, Culture and Sport of the Government of the Canary Islands, in collaboration with Las Palmas City Hall, the exhibition The Canary Islands, Volcanoes in the Ocean presents volcanism as a universal phenomenon and explains how volcanoes are formed, where they are situated and how they influence both the geography of and the peoples who inhabit volcanic areas, especially the Canary Islands. The show also devotes special attention to the role of science in the prevention and surveillance of active volcanoes.
The Canary Islands, Volcanoes in the Ocean, produced by Fundació ”la Caixa” and curated by the volcanologist Juan Carlos Carracedo, will be held under a marquee erected in Parque Santa Catalina, Las Palmas from 23 november 2002 to 6 January 2003.
Intended for the general public, the exhibition assembles interactive modules, dramatisations, maquettes and audiovisual presentations illustrating the different aspects of these natural phenomena which have formed islands, determined their morphology, altered the landscape and conditioned human coexistence.
Mars, Venus, the Moon and Jupiter’s satellites, among others, welcome the visitor to the show. The first section, Volcanoes in the solar system, reveals the diversity of origins of volcanism on the different planets and satellites, stressing the fact that this geological phenomenon does not affect Earth alone. Thus, one can witness ice volcanism, present on the satellites of Jupiter, Saturn and Neptune; volcanism driven by tidal force; volcanism associated with meteoric impact, on the Moon and Mercury; plate tectonics, present only on Earth; and volcanism originated by hot spots, on Venus, Mars and Earth (Hawaiian and Canary Island archipelagos).
A tridimensional volcano module with a light display simulating lava flows graphically illustrates the different parts of a volcano. Volcanoes are vents in the crust and it is through these openings that melted materials (magmas and gases) emerge from Earth’s interior. There are more than 1,500 active volcanoes worldwide and the majority of them are underwater (seas and ocean make up 71% of Earth’s surface). Their appearance at a particular time and place is not due to mere chance. On the contrary, their situation is largely determined by the limits between the tectonic plates forming Earth’s crust or by the hot spots where the magma rises. In this latter case, underwater volcanoes are formed. There are more than a million of these, although only some succeed in rising up to form oceanic volcanic islands.
The Canary Islands have a long magmatic history. Formed by active volcanoes more than 20 million years ago, this archipelago has gradually taken shape on the Atlantic Ocean floor. Some of these volcanoes have become islands while others, still forming under the water, will be islands sometime in the future.
Different stages can be seen in the evolution and distribution of volcanism in the Canary Islands. The more easterly islands appeared first while El Hierro and La Palma were the most recent. Within a million years this archipelago will probably include two new islands, Las Hijas, which currently rise only a few hundred metres from the ocean floor. An animated presentation shows how the present islands have emerged, as well as how and where those now in formation will surge.
Volcanoes are made up of different parts. The exterior, known as the volcanic edifice, is the result of successive eruptions. The relief of the different Canary Islands shows very tall volcanic edifices (Teide, officially 3,717 m high, in fact towers 8 km above its base) which have most of their height submerged. The geological history of the Canaries is the fruit of the construction and destruction of the numerous volcanic episodes that have created them. Little by little, the surging of large volcanoes and the sliding produced on the different islands have sculpted the major features of their spectacular landscape.
The earliest writings on volcanic activity in the Canary Island archipelago go back to the fifteenth century. The data found up to now on volcanic eruptions in the Canaries confirm that there have never been mortal victims. The exhibition includes numerous documents dealing with these eruptions, such as those compiled by the Real Audiencia de Canarias (Territorial High Court), on the intense eruption activity that took place in Lanzarote between 1730 and 1736, discovered in the General Archive of Simancas in 1989. The map painted in oils containing this information is the first volcanic risk map known to exist.
The Canary Islands are a magnificent example of harmony between mankind and volcanoes, a peaceful coexistence that has meant more advantages than drawbacks to the islands’ inhabitants. Among their positive aspects is the singularity of their landscapes, which not only shapes the identity of their people, traditions and cultural expressions but also serves as a tourist attraction. In fact, 12 million tourists visit this archipelago every year. Nevertheless, there are certain problematic factors: fragmentation of the territory, scarcity of resources such as water and soil, and volcanic risk which, while very limited, does exist.
Eruptions and prevention
An eruption consists of the emission and projection, more or less sudden, of volcanic materials that reach Earth’s surface. They can be divided into two major types: explosive (burning clouds, pyroclastic flows…) and effusive (more or less dense lava streams).
Active volcanoes alternate periods of calm with eruptive episodes. The show draws attention to some of the most famous historic eruptions. The consequences of these episodes often affect the entire planet. For example, the eruption of Krakatoa (Indonesia, 1883) not only killed 35,000 people but also produced a vast amount of dust in suspension, triggering red sunsets all over the world, a phenomenon which was reflected in pictures by famous painters of the time.
The show concludes with a section devoted to the role played by science in matters dealing with the prevention and monitoring of eruptions. Although volcanology has made huge advances and it can be said that, today, living close to an active volcano is safer than ever, it is still difficult to predict with accuracy what time an eruption will occur. Organised into networks, monitoring stations detect subtle movements by means of devices such as seismographs. The challenge facing volcanologists is to find out how, where and when a new eruption will take place.
Canarias, Volcanoes in the Ocean
from 23 november 2002 to 6 January 2003
Marquee in Parque Santa Catalina
35007 Las Palmas
Open to the public:Tuesdays to Fridays, 12:00 noon 2:00 p.m. and 6:00 9:00 p.m. Saturdays, Sundays and holidays, 11:00 a.m. 3:00 p.m. and 5:00 9:00 p.m. Closed Mondays. Closed 24, 25 and 31 december and 1 January.
ADMISSION FREE OF CHARGE