3. Wochenbericht M80/3

FS Meteor Reise M80/3 (Dakar, Senegal – Gran Canaria, Spanien) 3. Wochenbericht, 11. bis 17. Januar 201

1. Wochenbericht M80/3

FS Meteor Reise M80/3 (Dakar, Senegal – Gran Canaria, Spanien) 1. Wochenbericht, 27. Dezember 2009 bis 3. Januar, 201

4. Wochenbericht M80/3

FS Meteor Reise M80/3 (Dakar, Senegal – Gran Canaria, Spanien) 4. Wochenbericht, 18. bis 24. Januar 201

Cruise Report Poseidon Cruise POS270 : Exploring and sampling submarine volcanoes and collapse deposits off the western Canary Islands (El Hierro and La Palma), 02.03. - 15.03.2001, Las Palmas de Gran Canaria - Las Palmas de Gran Canaria

Project: "Beprobung und Untersuchung von submarinen Vulkaniten und Kollapsablagerungen im Bereich der westlichen Kanaren" (DFG: Ha 2100/6-1, Kl 1313/3-1

Synchronous degassing patterns of the neighbouring volcanoes Llaima and Villarrica in south-central Chile: the influence of tidal forces

The neighbouring volcanoes Villarrica and Llaima are two of the most active volcanoes in Chile and both currently degas continuously. We present a semi-continuous time series of SO2 fluxes for Villarrica and Llaima volcanoes. The time series was obtained using five scanning Mini-Differential Optical Absorption Spectrometers (Mini-DOAS, UV spectrometers) over 6 months (13 February to 31 July 2010) and is based on 6,829 scans for Villarrica and 7,165 scans for Llaima. Statistical analyses of the SO2 flux time series reveal a periodicity of degassing maxima about every 7 days, and further a conspicuous synchronicity of the degassing maxima and minima between the two volcanoes. Intra-day variations in SO2 fluxes also show a striking correlation between Villarrica and Llaima. All these patterns correlate well with the trend of the modelled solid Earth tide curves, where the 7-day degassing maxima correspond with both the fortnightly tidal maxima and minima. The intra-day degassing peaks mostly correlate well with the periods of maximum deformation rates during the diurnal tidal cycle, and further with semidiurnal minima in atmospheric pressure, a phenomenon we refer to as “the tidal pump”. As there is little time lag between the tidal action and the changes in degassing rates, we infer that degassing at both volcanoes is controlled by conduit convection, involving physical separation between gas and magma at comparatively shallow levels. Variations in daily degassing rates were up to a factor of ca. 12 and 10 for Villarrica and Llaima, respectively, without any noticeable changes in the periodicity. We thus suggest that the described cyclic variations must be taken into account for all comparable volcanoes when using gas monitoring as a tool for volcanic hazard mitigation

2. Wochenbericht M80/3

FS Meteor Reise M80/3 (Dakar, Senegal – Gran Canaria, Spanien) 2. Wochenbericht, 4. bis 10. Januar 201

4. Wochenbericht M141 „Azores Tephras“

FS METEOR Expedition M141 „Azores Tephras“ Wochenbericht 4, 24. September - 1. Oktober 201

Birth and evolution of seamounts in the Cape Verde archipelago

Tens of thousands of submarine volcanoes, so-called seamounts, with heights of more than a few hundred meters, exist in the world ocean. The Cape Verde archipelago is of volcanic origin and includes several prominent seamounts, which can give important information on the origin of submarine intraplate volcanism