Patterns of diversification on old volcanic islands as revealed by the woodlouse-hunter spider genus Dysdera (Araneae, Dysderidae) in the eastern Canary Islands

The faunas of volcanic islands must necessarily be introduced, and more recent introductions can be recognized by the patterns of their distributions. This is obvious in the Canary Islands, where we have spent 30 days studying distributions of Spirorbidae. We now regard these as a distinct family following Pillai (1970). We sampled all the major islands, by shore collecting and diving to about 10 m, and on almost all we found nine Mediterranean species, namely Protolaeospira striata (Quiévreux, 1963) and the eight opercular incubators (species of Pileolaria and Janua) that have been recorded from both Marseilles (Zibrowius, 1968) and Chios (Bailey, 1969).

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First study of the bat fossil record of the mid-Atlantic volcanic islands

Earth and Environmental Science Transactions of the Royal Society of Edinburgh ◽

10.1017/s1755691021000384 ◽

2021 ◽

pp. 1-15

Author(s):

Javier GONZÁLEZ-DIONIS ◽

Carolina CASTILLO RUIZ ◽

Penélope CRUZADO-CABALLERO ◽

Elena CADAVID-MELERO ◽

Vicente D. CRESPO

Keyword(s):

Atlantic Ocean ◽

Iberian Peninsula ◽

Central Europe ◽

Canary Islands ◽

Fossil Record ◽

Dental Morphology ◽

Lava Tubes ◽

El Hierro ◽

Volcanic Islands ◽

Fossil Data

ABSTRACT Bats are one of the most abundant and important mammals in ecosystems. However, their fossil record is scarce and fragile, making them difficult to find. Accordingly, there is no record of this group in the volcanic islands of the mid-Atlantic Ocean apart from the Canary Islands. This paper studies the first bat fossil record of the Canary Islands (Spain). The material studied is found within two Quaternary lava tubes, Cueva de los Verdes on Lanzarote and Cueva Roja on the island of El Hierro. The dental and humeral morphology and biometry are analysed and compared with current specimens. Among our results we highlight the first fossil data of two species endemic to the islands of the mid-Atlantic Ocean, Plecotus teneriffae and Pipistrellus maderensis, the former from the Canary Islands and the latter from the Azores, Madeira and the Canary Islands. We also confirm the presence of Pipistrellus kuhlii in the fossil record of the island of Lanzarote. No differences are observed between the dental morphology of the current and the fossil populations of P. maderensis and Pl. teneriffae. In the case of P. kuhlii, the populations of the Canary Islands and the Iberian Peninsula show differences in the paraconule with respect to the populations from central Europe. Palaeoecological studies of these taxa suggest that these islands presented a similar habitat when the sites were formed to the present-day habitat.

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Magnetic imaging of the feeding system of oceanic volcanic islands: El Hierro (Canary Islands)

Geophysical Journal International ◽

10.1111/j.1365-246x.2008.03723.x ◽

2008 ◽

Vol 173 (1) ◽

pp. 339-350 ◽

Cited By ~ 16

Author(s):

Isabel Blanco-Montenegro ◽

Iacopo Nicolosi ◽

Alessandro Pignatelli ◽

Massimo Chiappini

Keyword(s):

Canary Islands ◽

Feeding System ◽

El Hierro ◽

Magnetic Imaging ◽

Volcanic Islands

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The Holocene volcanism of El Hierro, Canary Islands

10.5194/egusphere-egu2020-7667 ◽

2020 ◽

Author(s):

Alejandro Rodríguez-González ◽

Meritxell Aulinas ◽

Francisco José Perez-Torrado ◽

Constantino Criado Hernández ◽

Maria del Carmen Cabrera ◽

...

Keyword(s):

Canary Islands ◽

Geological Mapping ◽

Submarine Eruption ◽

Volcanic Event ◽

The Holocene ◽

El Hierro ◽

La Palma ◽

Precise Knowledge ◽

Petrology And Geochemistry ◽

Volcanic Islands

El Hierro is, together with La Palma, the youngest island of the Canarian Archipelago. Both islands are in the shield stage of their volcanic growth, which implies a high volcanic activity during the Holocene period. The submarine eruption occurred in October 2011 in the SSE rift of El Hierro evidenced the active volcanic character of the island. Even so, despite the numerous scientific works published following the submarine eruption (most of them centered to understand such volcanic event), there is still a lack of precise knowledge about the Holocene subaerial volcanism of this island. The LAJIAL Project focuses on solving this knowledge gap.The Holocene subaerial volcanism of El Hierro generates fields of monogenetic volcanoes linked to the three systems of rifts present on the island. Its eruptive mechanisms are typically Strombolian although there are also phreato-Strombolian events. The most recent eruptions frequently form lava on coastal platforms, which are considered after the last glacial maximum (approx. 20 ka BP). The most developed coastal platforms in El Hierro are at the ends of the rifts and in the interior of the El Golfo depression. This geomorphological criterion shows that more than thirty subaerial eruptions have taken place in El Hierro since approx. 20 ka BP. In addition, there are many apparently recent volcanic edifices far from the coast.The research of the most recent volcanism of the island, the last 11,700 years of the Holocene, covers a long enough period whereas it is close to the present day. Thus, this period is the best to model the eruptive processes that will allow us to evaluate the future scenarios of the eruptive dynamics in El Hierro. The Project LAJIAL combines methodologies of geological mapping, geomorphology, GIS, chronostratigraphy, paleomagnetism, petrology and geochemistry to solve the Holocene eruptive recurrence rate in El Hierro, and to constrain the rift model of intraplate ocean volcanic islands.Financial support was provided by the Project LAJIAL (ref. PGC2018-101027-B-I00, MCIU/AEI/FEDER, EU). This study was carried out in the framework of the Research Consolidated Groups GEOVOL (Canary Islands Government, ULPGC) and GEOPAM (Generalitat de Catalunya, 2017 SGR 1494).

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The submarine volcanic succession of the basal complex of Fuerteventura, Canary Islands: A model of submarine growth and emergence of tectonic volcanic islands

Geological Society of America Bulletin ◽

10.1130/b25821.1 ◽

2006 ◽

Vol 118 (7-8) ◽

pp. 785-804 ◽

Cited By ~ 16

Author(s):

M. Gutierrez ◽

R. Casillas ◽

C. Fernandez ◽

K. Balogh ◽

A. Ahijado ◽

...

Keyword(s):

Canary Islands ◽

Basal Complex ◽

Volcanic Islands ◽

Volcanic Succession

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Velocity and attenuation models of Tenerife and La Palma (Canary Islands, Spain) through Ambient Noise Tomography.

10.5194/egusphere-egu2020-318 ◽

2020 ◽

Author(s):

Iván Cabrera ◽

Jean Soubestre ◽

Luca D'Auria ◽

Edoardo Del Pezzo ◽

José Barrancos ◽

...

Keyword(s):

Group Velocity ◽

Canary Islands ◽

Ambient Noise ◽

Dispersion Curves ◽

Ambient Noise Tomography ◽

Geothermal Exploration ◽

La Palma ◽

Cross Correlations ◽

Attenuation Models ◽

Volcanic Islands

Tenerife and La Palma are active volcanic islands belonging to the Canarian archipelago. The island of La Palma is the most occidental and volcanically active island of the archipelago. The youngest volcanic rocks are located in the Cumbre Vieja volcanic complex, a fast-growing North-South ridge in the southern half part of the island. On the other hand, the central part of Tenerife island hosts the Teide composite volcano, the third tallest volcano on Earth measured from the ocean floor. The volcanic system of the island extends along three radial dorsals, where most of the historical eruptions occurred. Those two volcanic islands have potential geothermal resources that could be exploited to increase the percentage of renewable energy in the Canary Islands.&#160;The main objective of this work is the use of Ambient Noise Tomography (ANT) to determine high-resolution seismic velocity and attenuation models of the first few kilometres of the crust, in order to detect anomalies potentially related to active geothermal reservoirs. In the case of Tenerife, previous tomographic studies were performed on the island using active seismic data. They allowed to image the structure of the first 8 km depth. However, for the purpose of geothermal exploration, a higher spatial resolution is needed for the first few kilometres and the determination of the shear wave velocity has a particular importance when searching for fluid reservoirs. In the case of La Palma, no seismic tomography was performed yet.&#160;To realize the ANT, we deployed temporary broadband seismic networks in the two islands. In total, we deployed seismic stations on 41 measurements points in Tenerife and 23 points in La Palma. The campaigns lasted at least 1 month, using jointly the permanent seismic network Red S&#237;smica Canaria (C7) operated by INVOLCAN. After performing standard data processing to retrieve Green&#8217;s functions from cross-correlations of ambient noise, we retrieved the dispersion curves using the FTAN (Frequency Time ANalysis) technique. The inversion of dispersion curves to obtain group velocity maps was performed using a novel non-linear multiscale tomographic approach. The forward modelling of surface waves traveltimes was implemented using a shortest-path algorithm which takes the topography into account. The method consists of progressive non-linear inversion steps at increasing resolution. This technique allows retrieving 2D group velocity models in presence of strong velocity contrasts with up to 100% of relative variation.&#160;In parallel with velocity model, we retrieved maps of seismic attenuation (i.e. quality factor Q) retrieved from the coda envelope decay of noise cross-correlations (Q-coda). For each source-receiver pair, a Q-coda value was calculated, and mapped to the target area by using 2D empirical sensitivity kernels for diffusion (Del Pezzo and Iba&#241;ez, 2019). We compared 2D velocity and attenuation images at different dominant periods, evidencing structural features for Tenerife and La Palma islands which seem to be relevant for the purpose of geothermal exploration.

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