The 2011 submarine volcanic eruption in El Hierro (Canary Islands)

Forty years after the Teneguía Volcano (La Palma, 1971), a submarine eruption took place off the town of La Restinga, south of El Hierro, the smallest and youngest island of the Canarian Archipelago. Precursors allowed an early detection of the event and its approximate location, suggesting it was submarine. Uncertainties derived from insufficient scientific information available to the authorities during the eruption, leading to disproportionate civil protection measures, which had an impact on the island's economy-based primarily on tourism-while residents experienced extra fear and distress. © 2012 Blackwell Publishing Ltd, The Geologists' Association & The Geological Society of London.Peer Reviewe

The 2011 submarine volcanic eruption in El Hierro (Canary Islands)

Forty years after the Teneguía Volcano (La Palma, 1971), a submarine eruption took place off the town of La Restinga, south of El Hierro, the smallest and youngest island of the Canarian Archipelago. Precursors allowed an early detection of the event and its approximate location, suggesting it was submarine. Uncertainties derived from insufficient scientific information available to the authorities during the eruption, leading to disproportionate civil protection measures, which had an impact on the island's economy-based primarily on tourism-while residents experienced extra fear and distress. © 2012 Blackwell Publishing Ltd, The Geologists' Association & The Geological Society of London.Peer Reviewe

The ongoing volcanic eruption of El Hierro, Canary Islands

El Hierro, the youngest of the Canary Islands (Spain), is no stranger to hazards associated with volcanic activity or to efforts to minimize the effects of these hazards on local communities. As early as 1793, administrative records of El Hierro indicate that a swarm of earthquakes was felt by locals; fearing a greater volcanic catastrophe, the first evacuation plan of an entire island in the history of the Canaries was prepared. The 1793 eruption was probably submarine with no appreciable consequences other than that the earthquakes were felt [Carracedo, 2008]; over the next roughly 215 years the island was seismically quiet. Yet seismic and volcanic activity are expected on this youngest Canary Island due to its being directly above the presumed location of the Canary Island hot spot, a mantle plume that feeds upwelling magma just under the surface, similar to the Hawaiian Islands. Because of this known geologic activity, the Spanish Instituto Geogrfco Nacional (IGN) has managed geophysical monitoring of the island since the beginning of the 1990s.Peer Reviewe

Open-system processes in the differentiation of mafic magma in the Teide–Pico Viejo succession, Tenerife

<p>Oceanic island basalts are commonly thought to differentiate by fractional crystallization, yet closed-system fractionation models have so far failed to reproduce major and trace element variations observed in mafic lavas from the Teide–Pico Viejo stratovolcano complex on Tenerife. Here, new high-precision plagioclase trace element data are fed into such a fractionation model. The results confirm that fractionation of phenocrysts found in the lavas does not reproduce trace element variations, in particular enrichment of Sr and Zr observed in the Teide–Pico Viejo mafic suite. This enrichment of Sr and Zr is tested by an energy-constrained recharge, assimilation and fractional crystallization (EC-RAFC) model at high <em>T</em> and low Δ<em>T</em> intervals, consistent with previously determined magma storage beneath Tenerife at sub-Moho depths. Published mineral–melt equilibrium relations using the plagioclase anorthite content (0.4 < <em>X</em>_An < 0.8) constrain the temperature during differentiation. Gabbroic xenoliths found in Tenerife lavas are assumed as contaminant. Enrichment of Sr and Zr in the Teide mafic suite is reproduced by this combined assimilation and fractional crystallization model, as assimilation causes higher degrees of enrichment in incompatible trace elements than is possible by crystal fractionation alone. Recycling of plutonic roots may thus have significantly enriched trace elements in the primitive lavas of the Teide–Pico Viejo succession. </p

Volatile dilution during magma injections and implications for volcano explosivity

Magma reservoirs underneath volcanoes grow through episodic emplacement of magma batches. These pulsed magma injections can substantially alter the physical state of the resident magma by changing its temperature, pressure, composition, and volatile content. Here we examine plagioclase phenocrysts in pumice from the 2014 Plinian eruption of Kelud (Indonesia) that record the progressive capture of small melt inclusions within concentric growth zones during crystallization inside a magma reservoir. High-spatial-resolution Raman spectroscopic measurements reveal the concentration of dissolved H2O within the melt inclusions, and provide insights into melt-volatile behavior at the single crystal scale. H2O contents within melt inclusions range from ∼0.45 to 2.27 wt% and do not correlate with melt inclusion size or distance from the crystal rim, suggesting that minimal H2O was lost via diffusion. Instead, inclusion H2O contents vary systematically with anorthite content of the host plagioclase (R2 = 0.51), whereby high anorthite content zones are associated with low H2O contents and vice versa. This relationship suggests that injections of hot and H2O-poor magma can increase the reservoir temperature, leading to the dilution of melt H2O contents. In addition to recording hot and H2O-poor conditions after these injections, plagioclase crystals also record relatively cold and H2O-rich conditions such as prior to the explosive 2014 eruption. In this case, the elevated H2O content and increased viscosity may have contributed to the high explosivity of the eruption. The point at which an eruption occurs within such repeating hot and cool cycles may therefore have important implications for explaining alternating eruptive styles

Geological Hazards in the Teide Volcanic Complex

The island of Tenerife displays contrasted densities of population, from the densely occupied coastal zones (including tourist resorts, airport, energy facilities, etc.) to the sparsely populated forests and mountainous highlands, where most of the recent volcanic events are located. Considering the low frequency of historical eruptions (compared to Hawaii or Reunion Island for example), the assessment of geological hazards must also rely on the analysis and interpretation of prehistorical events, going back to at least the Late Quaternary. In this chapter, we review the hazards related to Teide’s volcanism, but also those from increased seismicity and from slope instability. We discuss the origin of low magnitude earthquakes, and particularly the 2004 episode of unrest. New estimates on cumulative volumes for resurfacing by lava flows during the last few thousand years are provided to serve as a tool for building a lava flow hazard map of Tenerife. Hazards related to explosiveactivity are also considered and although possible, with phreatomagmatic eruptions being the most likely style anticipated, explosive events are of relatively low probability at Teide in the near futurePeer Reviewe

Evolution of ocean island rifts: the northeast rift-zone of Tenerife, Canary Islands

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Research Report in the Framework of the Project Seminar on Tourism organized by Prof. Dr. Bernhard Giesen (Winter Seminar 06/07)

The empirical study results from fieldwork on two South German castles, Burg Hohenzollern and Meersburg. Its aim is to inquire into the social construction of tourism, i.e. to grasp touristic experiences in statu nascendi. Starting with the assumption that modern travelling is linked to the search of the sacred, the central question was how exactly the crossing from everyday life to festivity happens. The collected data suggest, however, that a journey, at least a journey to a medieval castle in Southern Germany, is not just a singular transcendence from the ordinary to the extraordinary. Tourists can rather be observed how they permanently shift between everyday life and festivity. In this sense order and chaos, fact and fiction, and seriousness and playfulness constitute each other