Seismic full waveform inversion in archaeological prospecting

Seismic full waveform inversion is introduced as novel high-resolution imaging tool in archaeological prospection. The full waveform inversion approach allows the high-resolution characterization of low-contrast sedimentary layers, high-contrast stone wall structures and air-filled cavities

HOAPS precipitation validation with ship-borne rain gauge measurements over the Baltic Sea

Global ocean precipitation is an important part of the water cycle in the climate system. A number of efforts have been undertaken to acquire reliable estimates of precipitation over the oceans based on remote sensing and reanalysis modelling. However, validation of these data is still a challenging task, mainly due to a lack of suitable in situ measurements of precipitation over the oceans. In this study, validation of the satellite-based Hamburg Ocean Atmosphere Parameters and fluxes from Satellite data (HOAPS) climatology was conducted with in situ measurements by ship rain gauges over the Baltic Sea from 1995 to 1997. The ship rain gauge data are point-to-area collocated against the HOAPS data. By choosing suitable collocation parameters, a detection rate of up to about 70% is achieved. Investigation of the influence of the synoptic situation on the detectability shows that HOAPS performs better for stratiform than for convective precipitation. The number of collocated data is not sufficient to validate precipitation rates. Thus, precipitation rates were analysed by applying an interpolation scheme based on the Kriging method to both data sets. It was found that HOAPS underestimates precipitation by about 10%, taking into account that precipitation rates below 0.3 mm h−1 cannot be detected from satellite information

Geophysikalische Methoden zur Bewertung potenzieller Standorte für die Grundwassergewinnung

Complex geology in glacial terrain makes groundwater exploration challenging for water supply companies. Abrupt lateral changes of geological conditions, for example, raise the risk of unsuccessful exploration drilling. At some locations, local water supply companies experience a large number of dry wells, raising the need for better exploration approaches. The use of geophysical techniques enables the detection and characterization of subsurface structures in terms of aquifers and aquitards. We present two examples in which seismic and resistivity methods are combined for subsurface characterization. A thrust structure is detected in the Varde study area in Denmark and a channel structure is mapped in the Hamburg-Sülldorf study area in Germany. The different imaging characteristics of seismic P‑ and S‑waves are demonstrated. The combination of seismic and resistivity methods enables delineating groundwater-bearing and groundwater-barrier layers down to a depth of 150 m.Interreg North Sea Region ProgrammeLeibniz-Institut für Angewandte Geophysik (3464

Geophysical methods help to assess potential groundwater extraction sites

Complex geology in glacial terrain makes groundwater exploration challenging for water supply companies. Abrupt lateral changes of geological conditions, for example, raise the risk of unsuccessful exploration drilling. At some locations, local water supply companies experience a large number of dry wells, raising the need for better exploration approaches. The use of geophysical techniques enables the detection and characterization of subsurface structures in terms of aquifers and aquitards.We present two examples in which seismic and resistivity methods are combined for subsurface characterization. A thrust structure is detected in the Varde study area in Denmark and a channel structure is mapped in the Hamburg-Sülldorf study area in Germany. The different imaging characteristics of seismic P‑ and S‑waves are demonstrated. The combination of seismic and resistivity methods enables delineating groundwater-bearing and groundwater-barrier layers down to a depth of 150 m

Von der Nekropole zum Siedlungsplatz. Bericht über die Grabungskampagnen 2018 und 2019 in der Petosiris-Nekropole von Tuna el-Gebel

Ausgrabungen und Georadarmessungen in der Nekropole Tuna el-Gebel haben 2018 und 2019 neue Erkenntnisse über das Areal ergeben. Teilweise freigelegt wurden ein Steinbau (GB 73) und ein Gebäude aus ungebrannten Lehmziegeln (GB 72). Der Steinbau wurde in der Kaiserzeit als Grabbau genutzt, darüber hinaus verweist die Keramik auf eine Nachnutzung in der Spätantike. Die Anzahl und die Typen der Gefäße sprechen für die Ansiedlung einer größeren Gruppe von Menschen. GB 72 war zweistöckig und verfügte über ungewöhnliche Kultinstallationen vor der Fassade, die im Grabkontext zu deuten sind. Die Architektur verweist zudem auf eine diverse Nutzung des Gebäudes, etwa als Grabhaus und Einbalsamierungsstätte. Die geophysikalische Prospektion erschloss den östlichen Teil der Nekropole und ergänzte den Survey von 2007 und 2010. Die hohe Auflösung und die Kombination der Methoden ermöglichen eine genaue Differenzierung der Gebäudetypen sowie die Erstellung detaillierter Pläne der Nekropole. Zudem sind in den Radargrammen Störungen zu erkennen, die von Grabräubern herrühren.Excavations and georadar measurements in the Tuna el-Gebel necropolis in 2018 and 2019 have revealed new information about the site. A stone building (GB 73) and a building made of adobe bricks (GB 72) were partially exposed. The stone building was used as a tomb in the imperial period; moreover, the ceramics indicate a subsequent use in late antiquity. The number and types of vessels suggest the settlement of a larger group of people. GB 72 had two storeys and provided unusual cult installations in front of the façade, which are to be interpreted as belonging to the funerary context. According to the architecture the building had various uses, for instance as a tomb and an embalming place. The geophysical prospection was carried out in the eastern part of the necropolis and supplemented the survey of 2007 and 2010. The high resolution and the combination of methods permit a precise differentiation of the building types as well as the creation of detailed maps of the necropolis. In addition, the radargrams show disturbances caused by grave robbers

Constraining electric resistivity tomography by direct push electric conductivity logs and vibracores: An exemplary study of the Fiume Morto silted riverbed (Ostia Antica, western Italy)

The inversion of geoelectric data is nonunique. Therefore, electric resistivity tomography (ERT) usually results in different subsurface models that fit observed apparent resistivity values equally well. To reduce the uncertainty, constraints on the geometry and resistivity of subsurface structures can be incorporated into the ERT inversion. We test different ways of constraining ERT by applying (1) improved starting models, (2) structural constraints, and (3) structural and resistivity constraints. A priori information is needed for these approaches, which is acquired from direct push electrical conductivity (DP-EC) logs and vibracores in our study. We found that adapting high vertical resolution of DP-EC logs to coarser ERT resolution requires blocking of the logs. These blocked logs can be used for constraining the ERT inversion with resistivity and structural constraints along so-called regions around the log locations, which was found to be the best approach. In this case, ground truthing with additional DP-EC logs that were not used for constraining showed the lowest root-mean-square error between logs and ERT model

Pergamon, Türkei. Die Arbeiten des Jahres 2017

The work of the Pergamon excavation in 2017 concentrated on the exploration of the Hellenistic residence city and its surroundings within the framework of the current research programme, whose field work could be completed. The focus was on geophysical prospections and stratigraphic trenches on the burial mound Yığma Tepe. To test hypotheses on the development of the settlement history of the city hill of Pergamon, Bau X on the western slope was examined. The survey of the Kane-peninsula was finished; it provided unexpected insights into the importance of the site for traffic and trade in the microregion. The extensive monument preservation measures at Pergamon concentrated on the Gymnasion and the Red Hall. A detailed preliminary report, which contains also information about other fields of activity such as the study of elite burial practises, will be published in “Archäologischer Anzeiger” 2018/2

Pergamon, Türkei: Die Arbeiten des Jahres 2015

The activities of the Pergamon-excavation in 2015 were part of the continuing research program on the urban organism of the Hellenistic residential city and on Pergamon´s countryside. The program also includes studies of the ancient necropolis and the natural sanctuaries as integral elements within the presentation of suburbs and hinterland. The campaign focused on (1) geophysical prospection and archaeological sondages at the monumental tumulus Yiğma Tepe, (2) the completion of the excavation within the alleged banquet-building at the northern east-slope, (3) the archaeological and architectural study of the Lower Agora, (4) the continuation and almost completion of the Kane-Peninsula (Kara Dağ) regional harbor survey, (5) the extensive conservation and restoration works at the Red Hall and the Gymnasion of Pergamon. A detailed preliminary report, which contains also information about other fields of activity such as palaeo-anthropology or dendrochronology, will be published in “Archäologischer Anzeiger” 2015/2