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

1. Wochenbericht M175 Transformers II

FS METEOR Expedition M175 „Transformers II“, 02.- 28.06.2021, Emden - Emde

2. Wochenbericht M175 Transformers II

FS METEOR Expedition M175 „Transformers II“, 7. - 13. Juni 202

Meteorological influence on the seasonal and diurnal variability of the dispersion of volcanic emissions in Nicaragua: a numerical model

Nicaragua comprises seven historically active volcanoes (Cosigüina, San Cristobal, Telica, Cerro Negro, Momotombo, Masaya, and Concepcion), five of which are in a state of continuous degassing. Published measurements of the atmospheric dispersion of continuous emissions from Nicaraguan volcanoes, the chemical and aerosol microphysical modifications of the released gases and aerosols, and related acid deposition and impacts on the environment cover only short periods of time. We applied a three-dimensional atmosphere-chemistry/aerosol numerical model over Central America focussing on Nicaraguan volcanic emissions for month long simulation periods during the dry and wet seasons of 2003. The model is able to reproduce observed monthly precipitation and wind speed throughout the year 2003. Model results for near surface SO2 concentrations and SO2 dry deposition fluxes around Masaya volcano are in very good agreement with field measurements. During the dry season, oxidation of SO2 to sulphate plays only a minor role downwind of the Nicaraguan volcanoes and over the Pacific Ocean, whereas SO2 released from Arenal and Poas in Costa Rica is oxidised to sulphate much faster and closer to the volcanoes due to higher humidity and cloud water availability. During the wet season, more variable wind conditions lead to reduced dispersion of SO2 over the Pacific Ocean and increased dispersion inland. The availability of liquid water in the atmosphere favours sulphate formation close to the Nicaraguan volcanoes via aqueous phase oxidation and represents another limitation for the dispersion of SO2. Strong precipitation removes sulphate quickly from the atmosphere by wet deposition. Atmospheric SO2 concentrations and in particular dry deposition close to the volcanoes show a pronounced diurnal cycle

2. Wochenbericht M80/3

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