TY - JOUR A1 - Haberland, Christian A1 - Hampe, Oliver A1 - Autenrieth, Marijke A1 - Voss, Manja T1 - Balaenoptera borealis Lesson, 1828 BT - rediscovery of a holotype JF - Mammalia N2 - The whereabouts of the Balaenoptera borealis holotype, the skeleton of a 1819 stranded specimen, have been unknown since the World War II (WWII). Due to nomenclatural confusion, deficient documentation, and finally WWII bombing, which destroyed predominantly cetacean material in the Museum fib Naturkunde Berlin (MfN), the type skeleton of the sei whale sank into oblivion. Construction activities enabled a recent search and study on the remaining whale material. Here, we provide evidence that the type specimen was not destroyed. On the basis of species-wide and individual characters of the type material such as the shape of cranial elements and the pattern of the maxillary foramina, we show that the skull and mandibles, the vertebral column (except the atlas), and the ribs of the holotype remain intact. Further evidence that these skeletal remains belong to the previously missing holotype is provided by the characteristics of the spine. In addition, we analyzed ancient DNA from bone samples and confirm they are B. borealis, and the occurrence of same mitochondrial haplotypes indicate that the bones belong to the same individual. Additionally, a blue inscription was discovered at the caudal epiphysis of a thoracic vertebra; historical research matched this inscription with the material belonging to the former Anatomical-Zootomical Museum, from which the holotype was once bought. KW - Baltic Sea KW - holotype KW - museum collection KW - sei whale KW - skeleton Y1 - 2019 U6 - https://doi.org/10.1515/mammalia-2017-0149 SN - 0025-1461 SN - 1864-1547 VL - 83 IS - 4 SP - 343 EP - 351 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Planert, Lars A1 - Behrmann, Jan H. A1 - Jokat, Wilfried A1 - Fromm, Tanja A1 - Ryberg, Trond A1 - Weber, Michael A1 - Haberland, Christian T1 - The wide-angle seismic image of a complex rifted margin, offshore North Namibia: Implications for the tectonics of continental breakup JF - Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth N2 - Voluminous magmatism during the South Atlantic opening has been considered as a classical example for plume related continental breakup. We present a study of the crustal structure around Walvis Ridge, near the intersection with the African margin. Two wide-angle seismic profiles were acquired. One is oriented NNW–SSE, following the continent–ocean transition and crossing Walvis Ridge. A second amphibious profile runs NW–SE from the Angola Basin into continental Namibia. At the continent–ocean boundary (COB) the mafic crust beneath Walvis Ridge is up to 33 km thick, with a pronounced high-velocity lower crustal body. Towards the south there is a smooth transition to 20–25 km thick crust underlying the COB in the Walvis Basin, with a similar velocity structure, indicating a gabbroic lower crust with associated cumulates at the base. The northern boundary of Walvis Ridge towards the Angola Basin shows a sudden change to oceanic crust only 4–6 km thick, coincident with the projection of the Florianopolis Fracture Zone, one of the most prominent tectonic features of the South Atlantic ocean basin. In the amphibious profile the COB is defined by a sharp transition from oceanic to rifted continental crust, with a magmatic overprint landward of the intersection of Walvis Ridge with the Namibian margin. The continental crust beneath the Congo Craton is 40 km thick, shoaling to 35 km further SE. The velocity models show that massive high-velocity gabbroic intrusives are restricted to a narrow zone directly underneath Walvis Ridge and the COB in the south. This distribution of rift-related magmatism is not easily reconciled with models of continental breakup following the establishment of a large, axially symmetric plume in the Earth's mantle. Rift-related lithospheric stretching and associated transform faulting play an overriding role in locating magmatism, dividing the margin in a magma-dominated southern and an essentially amagmatic northern segment. KW - Wide-angle seismic KW - Crustal structure KW - Walvis Ridge KW - Hotspot KW - Rifted continental margin KW - South Atlantic Y1 - 2017 U6 - https://doi.org/10.1016/j.tecto.2016.06.024 SN - 0040-1951 SN - 1879-3266 VL - 716 SP - 130 EP - 148 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Haberland, Christian A1 - Rietbrock, Andreas A1 - Lange, Dietrich A1 - Bataille, Klaus A1 - Hofmann, S. T1 - Interaction between forearc and oceanic plate at the south-central Chilean margin as seen in local seismic data JF - Geophysical research letters N2 - We installed a dense, amphibious, temporary seismological network to study the seismicity and structure of the seismogenic zone in southern Chile between 37° and 39°S, the nucleation area of the great 1960 Chile earthquake. 213 local earthquakes with 14.754 onset times were used for a simultaneous inversion for the 1‐D velocity model and precise earthquake locations. Relocated artificial shots suggest an accuracy of the earthquake hypocenter of about 1 km (horizontally) and 500 m (vertically). Crustal events along trench‐parallel and transverse, deep‐reaching faults reflect the interseismic transpressional deformation of the forearc crust due to the subduction of the Nazca plate. The transverse faults seems to accomplish differential lateral stresses between subduction zone segments. Many events situated in an internally structured, planar seismicity patch at 20 to 40 km depth near the coast indicate a stress concentration at the plate's interface at 38°S which might in part be induced by the fragmented forearc structure. Y1 - 2006 U6 - https://doi.org/10.1029/2006GL028189 SN - 0094-8276 VL - 33 IS - 23 PB - Union CY - Washington ER - TY - JOUR A1 - Ryberg, Trond A1 - Haberland, Christian A1 - Haberlau, Thomas A1 - Weber, Michael H. A1 - Bauer, Klaus A1 - Behrmann, Jan H. A1 - Jokat, Wilfried T1 - Crustal structure of northwest Namibia: Evidence for plume-rift-continent interaction JF - Geology N2 - The causes for the formation of large igneous provinces and hotspot trails are still a matter of considerable dispute. Seismic tomography and other studies suggest that hot mantle material rising from the core-mantle boundary (CMB) might play a significant role in the formation of such hotspot trails. An important area to verify this concept is the South Atlantic region, with hotspot trails that spatially coincide with one of the largest low-velocity regions at the CMB, the African large low shear-wave velocity province. The Walvis Ridge started to form during the separation of the South American and African continents at ca. 130 Ma as a consequence of Gondwana breakup. Here, we present the first deep-seismic sounding images of the crustal structure from the landfall area of the Walvis Ridge at the Namibian coast to constrain processes of plume-lithosphere interaction and the formation of continental flood basalts (Parana and Etendeka continental flood basalts) and associated intrusive rocks. Our study identified a narrow region (<100 km) of high-seismic-velocity anomalies in the middle and lower crust, which we interpret as a massive mafic intrusion into the northern Namibian continental crust. Seismic crustal reflection imaging shows a flat Moho as well as reflectors connecting the high-velocity body with shallow crustal structures that we speculate to mark potential feeder channels of the Etendeka continental flood basalt. We suggest that the observed massive but localized mafic intrusion into the lower crust results from similar-sized variations in the lithosphere (i.e., lithosphere thickness or preexisting structures). Y1 - 2015 U6 - https://doi.org/10.1130/G36768.1 SN - 0091-7613 SN - 1943-2682 VL - 43 IS - 8 SP - 739 EP - 742 PB - American Institute of Physics CY - Boulder ER - TY - JOUR A1 - Overduin, Pier Paul A1 - Haberland, Christian A1 - Ryberg, Trond A1 - Kneier, Fabian A1 - Jacobi, Tim A1 - Grigoriev, Mikhail N. A1 - Ohrnberger, Matthias T1 - Submarine permafrost depth from ambient seismic noise JF - Geophysical research letters N2 - Permafrost inundated since the last glacial maximum is degrading, potentially releasing trapped or stabilized greenhouse gases, but few observations of the depth of ice-bonded permafrost (IBP) below the seafloor exist for most of the arctic continental shelf. We use spectral ratios of the ambient vibration seismic wavefield, together with estimated shear wave velocity from the dispersion curves of surface waves, for estimating the thickness of the sediment overlying the IBP. Peaks in spectral ratios modeled for three-layered 1-D systems correspond with varying thickness of the unfrozen sediment. Seismic receivers were deployed on the seabed around Muostakh Island in the central Laptev Sea, Siberia. We derive depths of the IBP between 3.7 and 20.7m15%, increasing with distance from the shoreline. Correspondence between expected permafrost distribution, modeled response, and observational data suggests that the method is promising for the determination of the thickness of unfrozen sediment. KW - submarine permafrost KW - ambient noise KW - Siberia KW - continental shelf Y1 - 2015 U6 - https://doi.org/10.1002/2015GL065409 SN - 0094-8276 SN - 1944-8007 VL - 42 IS - 18 SP - 7581 EP - 7588 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Fromm, T. A1 - Planert, Lars A1 - Jokat, Wilfried A1 - Ryberg, Trond A1 - Behrmann, Jan H. A1 - Weber, Michael H. A1 - Haberland, Christian T1 - South Atlantic opening: A plume-induced breakup? JF - Geology N2 - Upwelling hot mantle plumes are thought to disintegrate continental lithosphere and are considered to be drivers of active continental breakup. The formation of the Walvis Ridge during the opening of the South Atlantic is related to a putative plume-induced breakup. We investigated the crustal structure of the Walvis Ridge (southeast Atlantic Ocean) at its intersection with the continental margin and searched for anomalies related to the possible plume head. The overall structure we identify suggests that no broad plume head existed during opening of the South Atlantic and anomalous mantle melting occurred only locally. We therefore question the importance of a plume head as a driver of continental breakup and further speculate that the hotspot was present before the rifting, leaving a track of kimberlites in the African craton. Y1 - 2015 U6 - https://doi.org/10.1130/G36936.1 SN - 0091-7613 SN - 1943-2682 VL - 43 IS - 10 SP - 931 EP - 934 PB - American Institute of Physics CY - Boulder ER - TY - JOUR A1 - Braeuer, Benjamin A1 - Asch, Günter A1 - Hofstetter, Rami A1 - Haberland, Christian A1 - Jaser, D. A1 - El-Kelani, R. A1 - Weber, Michael H. T1 - Detailed seismicity analysis revealing the dynamics of the southern Dead Sea area JF - Journal of seismology N2 - Within the framework of the international DESIRE (DEad Sea Integrated REsearch) project, a dense temporary local seismological network was operated in the southern Dead Sea area. During 18 recording months, 648 events were detected. Based on an already published tomography study clustering, focal mechanisms, statistics and the distribution of the microseismicity in relation to the velocity models from the tomography are analysed. The determined b value of 0.74 leads to a relatively high risk of large earthquakes compared to the moderate microseismic activity. The distribution of the seismicity indicates an asymmetric basin with a vertical strike-slip fault forming the eastern boundary of the basin, and an inclined western boundary, made up of strike-slip and normal faults. Furthermore, significant differences between the area north and south of the Bokek fault were observed. South of the Bokek fault, the western boundary is inactive while the entire seismicity occurs on the eastern boundary and below the basin-fill sediments. The largest events occurred here, and their focal mechanisms represent the northwards transform motion of the Arabian plate along the Dead Sea Transform. The vertical extension of the spatial and temporal cluster from February 2007 is interpreted as being related to the locking of the region around the Bokek fault. North of the Bokek fault similar seismic activity occurs on both boundaries most notably within the basin-fill sediments, displaying mainly small events with strike-slip mechanism and normal faulting in EW direction. Therefore, we suggest that the Bokek fault forms the border between the single transform fault and the pull-apart basin with two active border faults. KW - Dead Sea basin KW - Microseismicity KW - Cluster KW - Pull-apart basin KW - Asymmetric basin KW - Transform fault Y1 - 2014 U6 - https://doi.org/10.1007/s10950-014-9441-4 SN - 1383-4649 SN - 1573-157X VL - 18 IS - 4 SP - 731 EP - 748 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Vales, Dina A1 - Dias, Nuno A. A1 - Rio, Ines A1 - Matias, Luis A1 - Silveira, Graca A1 - Madeira, Jose A1 - Weber, Michael H. A1 - Carrilho, Fernando A1 - Haberland, Christian T1 - Intraplate seismicity across the Cape Verde swell: A contribution from a temporary seismic network JF - Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth N2 - We present an analysis and characterization of the regional seismicity recorded by a temporary broadband seismic network deployed in the Cape Verde archipelago between November 2007 and September 2008. The detection of earthquakes was based on spectrograms, allowing the discrimination from low-frequency volcanic signals, resulting in 358 events of which 265 were located, the magnitudes usually being smaller than 3. For the location, a new 1-D P-velocity model was derived for the region showing a crust consistent with an oceanic crustal structure. The seismicity is located mostly offshore the westernmost and geologically youngest areas of the archipelago, near the islands of Santo Antao and Sao Vicente in the NW and Brava and Fogo in the SW. The SW cluster has a lower occurrence rate and corresponds to seismicity concentrated mainly along an alignment between Brava and the Cadamosto seamount presenting normal faulting mechanisms. The existence of the NW cluster, located offshore SW of Santo Antao, was so far unknown and concentrates around a recently recognized submarine cone field; this cluster presents focal depths extending from the crust to the upper mantle and suggests volcanic unrest No evident temporal behaviour could be perceived, although the events tend to occur in bursts of activity lasting a few days. In this recording period, no significant activity was detected at Fogo volcano, the most active volcanic edifice in Cape Verde. The seismicity characteristics point mainly to a volcanic origin. The correlation of the recorded seismicity with active volcanic structures agrees with the tendency for a westward migration of volcanic activity in the archipelago as indicated by the geologic record. (C) 2014 Elsevier B.V. All rights reserved. KW - Intraplate seismicity KW - Clustering KW - Local magnitude scale KW - Active volcanism KW - Cape Verde KW - Atlantic Ocean Y1 - 2014 U6 - https://doi.org/10.1016/j.tecto.2014.09.014 SN - 0040-1951 SN - 1879-3266 VL - 636 SP - 325 EP - 337 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Muksin, Umar A1 - Haberland, Christian A1 - Nukman, Mochamad A1 - Bauer, Klaus A1 - Weber, Michael H. T1 - Detailed fault structure of the Tarutung Pull-Apart Basin in Sumatra, Indonesia, derived from local earthquake data JF - Journal of Asian earth sciences N2 - The Tarutung Basin is located at a right step-over in the northern central segment of the dextral strike-slip Sumatran Fault System (SFS). Details of the fault structure along the Tarutung Basin are derived from the relocations of seismicity as well as from focal mechanism and structural geology. The seismicity distribution derived by a 3D inversion for hypocenter relocation is clustered according to a fault-like seismicity distribution. The seismicity is relocated with a double-difference technique (HYPODD) involving the waveform cross-correlations. We used 46,904 and 3191 arrival differences obtained from catalogue data and cross-correlation analysis, respectively. Focal mechanisms of events were analyzed by applying a grid search method (HASH code). Although there is no significant shift of the hypocenters (10.8 m in average) and centroids (167 m in average), the application of the double difference relocation sharpens the earthquake distribution. The earthquake lineation reflects the fault system, the extensional duplex fault system, and the negative flower structure within the Tarutung Basin. The focal mechanisms of events at the edge of the basin are dominantly of strike-slip type representing the dextral strike-slip Sumatran Fault System. The almost north south striking normal fault events along extensional zones beneath the basin correlate with the maximum principal stress direction which is the direction of the Indo-Australian plate motion. The extensional zones form an en-echelon pattern indicated by the presence of strike-slip faults striking NE SW to NW SE events. The detailed characteristics of the fault system derived from the seismological study are also corroborated by structural geology at the surface. (C) 2014 Elsevier Ltd. All rights reserved. KW - Focal mechanism KW - Seismicity KW - Structural geology KW - Extensional duplex KW - Flower structure KW - Sumatran fault KW - Pull-Apart Basin Y1 - 2014 U6 - https://doi.org/10.1016/j.jseaes.2014.09.009 SN - 1367-9120 SN - 1878-5786 VL - 96 SP - 123 EP - 131 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Braeuer, B. A1 - Asch, Günter A1 - Hofstetter, Rami A1 - Haberland, Christian A1 - Jaser, Darweesh A1 - El-Kelani, Radwan J.. A1 - Weber, Michael H. T1 - Microseismicity distribution in the southern Dead Sea basin and its implications on the structure of the basin JF - Geophysical journal international N2 - While the Dead Sea basin has been studied for a long time, the available knowledge about the detailed seismicity distribution in the area, as well as the deeper structure of the basin, is limited. Therefore, within the framework of the international project DESIRE (DEad Sea Integrated REsearch project), a dense temporary local seismological network was operated in the southern Dead Sea area. We use 530 local earthquakes, having all together 26 730 P- and S-arrival times for a simultaneous inversion of 1-D velocity models, station corrections and precise earthquake locations. Jackknife tests suggest an accuracy of the derived hypocentre locations of about 1 km. Thus, the result is the first clear image of the absolute distribution of the microseismicity of the area, especially in depth. The seismicity is concentrated in the upper crust down to 20 km depth while the lower limit of the seismicity is reached at 31 km depth. The seismic events at the eastern boundary fault (EBF) in the southern part of the study area represent the northward transform motion of the Arabian Plate along the Dead Sea Transform. North of the Boqeq fault the seismic activity represents the transfer of the motion in the pull-apart basin from the eastern to the western boundary. We find that from the surface downward the seismic events are tracing the boundary faults of the basin. The western boundary is mapped down to 12 km depth while the EBF reaches about 17 km depth, forming an asymmetric basin. One fifth of the data set is related to a specific cluster in time and space, which occurred in 2007 February at the western border fault. This cluster is aligned vertically, that is, it is perpendicular to the direction of the dominating left-lateral strike-slip movement at the main transform fault. KW - Seismicity and tectonics KW - Continental tectonics: strike-slip and transform KW - Asia Y1 - 2012 U6 - https://doi.org/10.1111/j.1365-246X.2011.05318.x SN - 0956-540X VL - 188 IS - 3 SP - 873 EP - 878 PB - Wiley-Blackwell CY - Malden ER -