ALBERT

Description: Near Reykjavik/Iceland, a "soft stimulation” geothermal experiment was performed in the frame of the DESTRESS project in 2019. The installed seismic stations consist of short period, and borehole stations in and around Geldinganes, NE of Reykjavik. The task of this network is the monitoring of the seismic events in the area around the stimulation site. The installation started in late 2018 with 6 short period stations (Reykjavik Energy). Since July 2019 additional seismic stations were integrated as a small scale array on the island Geldinganes and additional short period stations. A borehole geophone chain was installed with 17 short period 3-component geophones with a vertical spacing of 10 meter in the depth interval 1040m to 1200 m. Waveform data are available from the GEOFON data centre, under network code YG, and are embargoed until January 2025.

Description: The Bransfield Strait is a seismically active extensional rift located between the Antarctic Peninsula and the South Shetland Islands. The Strait is partly located on continental crust including areas within the transition to seafloor spreading. The amphibious seismic network BRAVOSEIS is an international effort focused on the seismological research of submarine volcanoes and rift dynamics in the Bransfield Strait. This network is the onshore component of the entire network consisting of 15 broadband land stations deployed in the South Shetland Islands and Antarctic Peninsula between January 2018 and February 2020. The offshore components (network code ZX) include 9 broadband ocean bottom seismometers (OBS) across the Central Bransfield Basin and a group of 6 hydrophone moorings spanning the rift area of 200 x 100 km2, with inter-station distance of ~30 km. Additionally, a smaller offshore array consisting of 15 short-period OBSs with an aperture of 20 km and a narrow inter-station distance of ~4 km was deployed around the Orca submarine volcanic edifice south of King George Island. The data will be used to study the geodynamics of the Bransfield Strait and the evolution of the incipient rifting zone in the domain where extension has been suggested. Seismological methods will include earthquake location, source mechanism, surface wave analysis with ambient noise and earthquake data, receiver function and shear wave splitting. The results may shed light on the crustal structure and tectonic regime in the region and image the location and extent of magma accumulations related to submarine volcanic structures. Finally, the results should provide clues to assess the internal processes that occur in the submarine volcanoes of the area undergoing rifting. Waveform data are available from the GEOFON data centre, under network code 5M and are embargoed until Mar 2024. Acknowledgments: We thank all participants in the BRAVOSEIS 2018, 2019, and 2020 cruises, with a special acknowledgement to Capt. Jose Emilio Regodon and his crew at R/V Hesperides; Capt. Juan Carlos Hernandez and his crew at Sarmiento de Gamboa; Miki Ojeda, Ezequiel Gonzalez, and all the UTM staff involved in the planification and realization of the surveys. We also thank the Spanish Polar Committee and institutions involved in the management of the Spanish Antarctic campaigns and the development of the Spanish Polar Program. We are grateful for the help and support that we always find in the personnel of the Antarctic Bases, especially the Spanish Bases Juan Carlos I and Gabriel de Castilla.

Description: Oldoinyo Lengai in the North Tanzanian Divergence is the only active natrocarbonatite volcano world-wide and presents an important endmember magmatic system in a young rift segment of the East African Rift System. This volcano typically experiences long-duration episodes of natrocarbonatitic effusions with intermittent short-duration explosive eruptions. To better understand the role of the stress interactions and magma plumbing on the eruptions dynamics, this study aims to constrain the subsurface magmatic architecture of Oldoinyo Lengai, and a zone of ongoing seismicity and intrusive activity below the extinct 1 Ma-old Gelai shield volcano and active Naibor Soito monogenetic cone field. Waveform data are available from the GEOFON data centre, under network code 9J, and are embargoed until November 2025.

Description: On 26th of November 2019 an Mw 6.4 earthquake ruptured near the port town of Durres, only 25 km from Tirana, the capital of Albania. The earthquake caused major damage and killed 51 people, making it the deadliest earthquake in 2019 worldwide. The mainshock was relatively deep (~25 km) and of thrust type. In December 2019, a Hazard and Risk team (HART) from German Center for Geosciences (GFZ), Karslruhe Institute of Technology (KIT) in cooperation with the Institute of Geosciences, Energy, Water and Environment (IGEWE) of the Polytechnic University of Tirana, Albania installed a 30-station seismic network in the epicentral region to record aftershocks. Stations were equipped with short-period (1 Hz or 4.5 Hz) 3-component seismometers and CUBE data loggers recording continuously 100 sps. Waveform data are available from the GEOFON data centre, under network code 9K under CC-BY 4.0 license and are embargoed until January 2024.

Description: The dataset is composed of Neo HySpex (VNIR/SWIR) hyperspectral imagery acquired during airplane overflights on June 6th, 2015 covering the Omongwa Pan located in the South-West Kalahari, Namibia. The dataset includes three cloud-free flight lines with 408 spectral bands ranging from VNIR to SWIR wavelength regions (0.4-2.5 µm). The dataset also includes Level 2A EnMAP-like imagery simulated using the end-to-end Simulation tool (EeteS). The overall goal of the campaign was to acquire imagery over the Omongwa Pan and use the spectral reflectance for the analyses of surface sediments, specifically the mineralogical composition of exposed surface evaporites / salts on the airborne and spaceborne scale. The data are highly novel and can be used to test estimation of surface sediment properties in a highly saline and dynamic environment.

Description: The dataset is composed of Neo HySpex (VNIR/SWIR) hyperspectral imagery acquired during the GFZ/DIMAP Geoarchive airborne campaign on June 6th, 2015 covering the Omongwa salt pan located in the South-West Kalahari, Namibia. The dataset includes 9 merged cloud-free flight lines with 408 spectral bands ranging from VNIR to SWIR wavelength regions (0.4-2.5 μm). The dataset also includes Level 2A EnMAP-like imagery simulated using the end-to-end Simulation tool (EeteS). The overall goal of the campaign was to test the potential of advanced optical hyperspectral remote sensing, or imaging spectroscopy, for the analysis of surface processes in the Omongwa salt pan and for the quantification of surface sediments. Specifically, the mineralogical composition of exposed evaporites such as halite, gypsum and calcite were investigated at the airborne and spaceborne scale, associated with comprehensive field campaigns, ich which spectral reflectance and ground-truth chemical data of field samples have been collected. The data are highly novel and can be used as testbeds for the development and validation of retrieval algorithms based on air- and space-borne hyperspectral imagery for estimation of surface sediment properties in a highly saline and dynamic environment.

Description: This interactive webpage contains supplementary information for the publication by Jamalreyhani et al., 2020: Seismicity related to the eastern sector of Anatolian escape tectonics: A seismic gap partly filled by the 24 January 2020 Mw 6.8 Elazığ-Sivrice earthquake.

Description: The Lake Junín Drilling Project, co-funded by the International Continental Scientific Drilling Program, ICDP, aims to provide a continuous paleoclimate record from lacustrine sediments, and to reconstruct the history of the continental records covering the glacial-interglacial cycles spanning more than 500 kyr. Lake Junín, also known as Chinchaycocha, is a shallow (maximum water depth of 12 m), inter-mountain high-elevation (at 4100 m a.s.l.) lake in the inner-tropics of the Southern Hemisphere that spans 300 km2 in the tropical Andes of Peru. Drill cores were recovered during summer 2015 from three drill sites on the lake. After the completion of coring operations in each hole, downhole logging measurements were performed in five of the 11 boreholes (1A, 1C, 1D, 2A and 3B) by the Operational Support Group of ICDP at GFZ Potsdam (OSG). The OSG logging data from Lake Junín Drilling Project is given here in three data formats. For each of the five boreholes all processed logging data are comprised in one composite logging data set, this set is given here both in ASCII text and in WellCAD format. Additionally, the raw sonic waveform data are in LIS format: • Composite logging data in ASCII text files (.txt) • Composite logging data in WellCAD format (.wcl) • Sonic raw data (waveforms) in LIS format (.lis) Detailed description is provided in the associated data description file.

Description: This dataset provides rheometric data of three viscous materials used for centrifuge experiments at the Tectonic Modelling Laboratory of CNR-IGG at the Earth Sciences Department of the University of Florence (Italy). The first material, PP45, is a mixture of a silicone (Polydimethylsiloxane or PDMS SGM36) and plasticine (Giotto Pongo). The PDMS is produced by Dow Corning and its characteristics are described by e.g. Rudolf et al. 2016a,b). Giotto Pongo is produced by FILA (Italy). Both components are mixed following a weight ratio of 100:45, and the final mixture has a density of 1520 kg m3. The second material, SCA705 is a mixture of Dow Corning 3179 putty, mixed with fine corundum sand and oleic acid with a weight ratio of 100:70:05 and a resulting density of 1660 kg m3. The final material, SCA7020 consists of the same components as SCA705, but with a slightly higher oleic acid content reflected in the weight ratio of 100:70:20. The mixture’s density is 1620 kg m3. The material samples have been analyzed in the Helmholtz Laboratory for Tectonic Modelling (HelTec) at GFZ German Research Centre for Geosciences in Potsdam using an Anton Paar Physica MCR 301 rheometer in a plate-plate configuration at room temperature (20˚C). Rotational (controlled shear rate) tests with shear rates varying from 10-4 to 1 s-1 were performed. Additional temperature tests were run with shear rates between 10-2 to 10-1 s-1 for a temperature range between 15 and 30˚C. According to our rheometric analysis, the materials all exhibit shear thinning behavior, with high power law exponents (n-number) for strain rates below 10-2s-1, while power law exponents are lower above that threshold.For PP45, the respective n-numbers are 4.8 and 2.6, for SCA705 6.7 and 1.5, and for SCA7020 9.1 and 2.0. The temperature tests show decreasing viscosities with increasing temperatures with rates of -3.8, -1.4 and -1.9% per ˚K for PP45, SCA705 and SCA7020, respectively. An application of the materials tested can be found in Zwaan et al. (2020).

Description: This data set includes videos depicting the surface evolution of 29 analogue models on crustal extension, as well as 4D CT imagery (figures and videos) of two of these experiments. The experiments examined the influence of the method for driving extension (orthogonal or rotational) on the interaction between rift segments using a brittle-viscous set-up. All experiments were performed at the Tectonic Modelling Laboratory of the University of Bern, Bern, Switzerland (UB). Brittle and viscous layers are both 4 cm thick, extension velocities are 8 mm/h so that a model duration of 5 h yields a total extension of 40 mm (e = ca. 13%, given an initial model width of ca. 30 mm). Next to the mode of extension (orthogonal or rotational), we also test the effect of the degree of onderlap (angle φ). Detailed descriptions of the experiments and monitoring techniques can be found in Zwaan et al. (2020).