1,721,394 research outputs found
Master track of SONNE cruise SO288 in 1 sec resolution (zipped, 14.2 MB)
No full textRaw data acquired by position sensors on board RV SONNE during expedition SO288 were processed to receive a validated master track which can be used as reference of further expedition data. During SO288 the motion reference unit Kongsberg SeaTex AS MRU-5 combined with Kongsberg SeaTex AS Seapath 320 and two GPS receivers SAAB MGL-4 were used as navigation sensors. Data were downloaded from DAVIS SHIP data base (https://dship.bsh.de) with a resolution of 1 sec. Processing and evaluation of the data is outlined in the data processing report. Processed data are provided as a master track with 1 sec resolution derived from the position sensors' data selected by priority and a generalized track with a reduced set of the most significant positions of the master track
Seismic reflection processed data of profile P05 (BGR18-205) during SONNE cruise SO267, Lau Basin, South Pacific Ocean
No full textThis seismic reflection line (214 km length) images the shallow crust in the Lau Basin, South Pacific Ocean. Data acquistion during December 2018 (Station SO267_43-1) using a 312 channel Sentinel RD streamer (3900 m active length) as recording unit and a 12 G-Gun array as source (volume: 84 liters, source point spacing: 50 m). Processing up to poststack time migration und depth conversion
2D Magnetic profile data crossing the Mangatolu Triple Junction and the Fonualei Rift Spreading Centre in the northern Lau Basin, measured along profile P02 during SONNE cruise SO267
No full textThe dataset comprises measurements of the total intensity of the magnetic field measured with a towed Overhauser sensor and calculated magnetic anomalies. The data were measured along a E-W trending profile at ~16°S in the northern Lau Basin and were acquired in January 2019 as part of the SO267 cruise
Gravity data of 2D profile crossing the Mangatolu Triple Junction and the Fonualei Rift Spreading Centre in the northern Lau Basin, measured along profile P02 during SONNE cruise SO267
No full textThe gravimetric data was acquired with a sea gravimeter KSS32-M system, which was installed on RV Sonne near its centre of gravity during the SO267 cruise. The instrumental drift of the data was approximated by repeated gravity observations in the harbour of Suva both at the beginning and at the end of the expedition. In order to tie the measurements to the International Gravity Standardization Net IGSN71, gravimetric measurements with a LaCoste&Romberg gravity metre, model G, no. 480 (LCR G480) were executed both at the pier next to RV Sonne and at the next absolute gravity reference station at the Mineral Resources Department in Suva, Fiji. Additional processing of the data comprised the correction of the Eötvös effect using navigation data and the subtraction of the normal gravity. Data was acquired along a E-W trending profile in the northern Lau Basin at ~ 16°S between the 13.01.2019 and the 14.01.2019
Master tracks in different resolutions of SONNE cruise SO288, Guayaquil - Valparaiso, 2022-01-15 - 2022-02-15
No full textRaw data acquired by position sensors on board RV SONNE during expedition SO288 were processed to receive a validated master track which can be used as reference of further expedition data. During SO288 the motion reference unit Kongsberg SeaTex AS MRU-5 combined with Kongsberg SeaTex AS Seapath 320 and two GPS receivers SAAB MGL-4 were used as navigation sensors. Data were downloaded from DAVIS SHIP data base (https://dship.bsh.de) with a resolution of 1 sec. Processing and evaluation of the data is outlined in the data processing report. Processed data are provided as a master track with 1 sec resolution derived from the position sensors' data selected by priority and a generalized track with a reduced set of the most significant positions of the master track
Seismic refraction and wide-angle reflection OBS data from profile P05 during SONNE cruise SO267 (ARCHIMEDES), Lau Basin
No full textThe dataset contains ocean bottom hydrophone (OBH) data acquired along profile P05 during RV Sonne Expedition SO267 (project ARCHIMEDES) to the Lau Basin, Southwestern Pacific in December 2018. This seismic refraction data set contains 34 OBS that all recorded the shots along the ~220 km long seismic transect successfully. Data for two different shot intervals (50m and 150m) were acquired shooting from east to west and from west to east respectively. An 84 l airgun array served as seismic source that was towed behind the vessel 8 m below sea surface. The data were processed using standard methods for relocation of the instrument at the seafloor, clock drift correction, deconvolution and filtering
Dehydration of subducting slow-spread oceanic lithosphere in the Lesser Antilles
No full textSubducting slabs carry water into the mantle and are a major gateway in the global geochemical water cycle. Fluid transport and release can be constrained with seismological data. Here we use joint active-source/local-earthquake seismic tomography to derive unprecedented constraints on multi-stage fluid release from subducting slow-spread oceanic lithosphere. We image the low P-wave velocity crustal layer on the slab top and show that it disappears beneath 60–100 km depth, marking the depth of dehydration metamorphism and eclogitization. Clustering of seismicity at 120–160 km depth suggests that the slab’s mantle dehydrates beneath the volcanic arc, and may be the main source of fluids triggering arc magma generation. Lateral variations in seismic properties on the slab surface suggest that serpentinized peridotite exhumed in tectonized slow-spread crust near fracture zones may increase water transport to sub-arc depths. This results in heterogeneous water release and directly impacts earthquakes generation and mantle wedge dynamics
Structure of the central Sumatran subduction zone revealed by local earthquake travel-time tomography using an amphibious network
No full textThe Sumatran subduction zone exhibits strong seismic and tsunamogenic potential with the prominent examples of the 2004, 2005 and 2007 earthquakes. Here, we invert travel-time data of local earthquakes for vp and vpĝ•vs velocity models of the central Sumatran forearc. Data were acquired by an amphibious seismometer network consisting of 52 land stations and 10 ocean-bottom seismometers located on a segment of the Sumatran subduction zone that had not ruptured in a great earthquake since 1797 but witnessed recent ruptures to the north in 2005 (Nias earthquake, Mw Combining double low line 8.7) and to the south in 2007 (Bengkulu earthquake, Mw Combining double low line 8.5). The 2-D and 3-D vp velocity anomalies reveal the downgoing slab and the sedimentary basins. Although the seismicity pattern in the study area appears to be strongly influenced by the obliquely subducting Investigator Fracture Zone to at least 200&thinsp;km depth, the 3-D velocity model shows prevailing trench-parallel structures at depths of the plate interface. The tomographic model suggests a thinned crust below the basin east of the forearc islands (Nias, Pulau Batu, Siberut) at ĝ1/4 180&thinsp;km distance to the trench. vp velocities beneath the magmatic arc and the Sumatran fault zone (SFZ) are around 5&thinsp;km&thinsp;sĝ'1 at 10&thinsp;km depth and the vpĝ•vs ratios in the uppermost 10&thinsp;km are low, indicating the presence of felsic lithologies typical for continental crust. We find moderately elevated vpĝ•vs values of 1.85 at ĝ1/4 150&thinsp;km distance to the trench in the region of the Mentawai Fault. vpĝ•vs ratios suggest an absence of large-scale alteration of the mantle wedge and might explain why the seismogenic plate interface (observed as a locked zone from geodetic data) extends below the continental forearc Moho in Sumatra. Reduced vp velocities beneath the forearc basin covering the region between the Mentawai Islands and the Sumatra mainland possibly reflect a reduced thickness of the overriding crust.</p
Microseismicity in the period 12/2018-01/2019 at the southern Fonualei Rift and Spreading Center, Lau Basin, with SEISAN waveform files and traveltime picks
No full textThis dataset includes earthuake location results from a 32-days long Ocean Bottom Seismometer (OBS) experiment conducted at the southern end of the Fonualei Rift and Spreading Center in the Lau Basin, southwestern Pacific. The experiment was conducted during RV Sonne cruise SO267, project ARCHIMEDES I. The accompanying zip-file "SEISAN_files.zip" includes raw waveform data for all earthquakes and the file "select.out" that includes all manual phase onset picks of all earthquakes. All data in the zipped archive "SEISAN_files.zip" may be processed and used with the SEISAN seismology software
Sub-bottom profiler data of the northern Lau Basin at ~16° during SONNE cruise SO267
No full textThe Atlas PARASOUND P70 system was used to acquire high resolution sub-bottom profiler data throughout most of the cruise. Two different waves with frequencies of ~18-20 kHz (primary high frequency, PHF) and a ~22-24 kHz wave were used to create a so-called secondary high (about 40-42 kHz, SHF) and a secondary low frequency (SLF) of about 4 kHz, which is used for the sub-bottom profiling. The opening angle of the transducer array is 4° by 5°, which corresponds to a footprint size of about 7 % of the water depth. Data was acquired along p02 of Sonne cruise SO267 which crosses the northern Fonualei Rift Spreading Centre and the southern Mangatolu Triple Junction about ~16° S
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