Archaeology at the Danube using non-invasive ground and aerial prospection methods to document prehistoric settlement traces at the Bisamberg near Vienna, Austria

To link prehistoric settlement activities with a modern mapping of existing monuments on the site, non-invasive aerial and terrestrial prospection methods are used. The LiDAR data catches the course of the presumed prehistoric rampart. The geomagnetic measurements display, among other things, the course of a 250 m long prehistoric ditch. Furthermore, ERT measurements reveal the rampart’s inner construction

Integrated archaeological and engineering geophysical investigation of the castle ruin Mödling (Austria)

An extensive multi-method investigation of a castle ruin has been conducted that extends the spectrum of geophysical methods used in archaeological prospection. For complex sites like a castle ruin, the incorporation of seismic and geoelectrical methods can facilitate the interpretation of ground penetrating radargrams, particularly in the existence of bedrock

Bridges to the past - the Roman settlement of Emmersdorf/Rosegg, Austria

A large-area archaeological prospection of a roman bridgehead settlement using aerial photography, magnetics and GPR was conducted. The roman bridgehead settlement of Emmerdorf/Rosegg is one of the best preserved Roman settlements in Austria

The more, the merrier? A multi-methodological survey at the Roman town of Carnuntum

We have newly discovered the garrison of the governor’s guard, the castra singularium, in the Roman Town of Carnuntum. For a more detailed research we decided to apply a multi-method research approach on this importent archaeological site. The analysis of the different geophysical prospection methods was carried out prior to an archaeological excavation. By excavating a small area, the interpretations of the non-destructive methods could be evaluated

Protected by shooting at it - the Öde Kloster and an associated Roman settlement within the military training area Bruckneudorf, Austria

The archaeological prospection focused on a multiphase fortified settlement. It was conducted as an integrated survey using airborne laserscanning (ALS) data, aerial photography, magnetics and GPR. The results show among other things that restricted military areas provide outstanding conditions for the preservation of archaeological sites

Large-scale motorised prospection along the “SuedLink” route in Lower Franconia

Large-scale archaeological prospection has proven itself as an essential tool in advance of a linear infrastructure project. The non-destructive survey is a basis for infrastructural planning and the protection of archaeological sites. More than 410 ha of high-resolution motorized geomagnetics were surveyed within six weeks. Such infrastructure projects can also be seen as an opportunity for archaeological research

Buried, forgotten and rediscovered - prospecting the Roman villae rusticae in the area of Flachgau in Salzburg, Austria

At six different villae rusticae sites in the Salzburger Flachgau high resolution motorized and non motorized magnetic and radar data was gained. The sites are well preserved due to sustainable agricultural use

Integrated land and water-borne geophysical surveys shed light on the sudden drying of large karst lakes in southern Mexico

Karst water resources play an important role in drinking water supply but are highly vulnerable to even slight changes in climate. Thus, solid and spatially dense geological information is needed to model the response of karst hydrological systems to such changes. Additionally, environmental information archived in lake sediments can be used to understand past climate effects on karst water systems. In the present study, we carry out a multi-methodological geophysical survey to investigate the geological situation and sedimentary infill of two karst lakes (Metzabok and Tzibaná) of the Lacandon Forest in Chiapas, southern Mexico. Both lakes present large seasonal lake-level fluctuations and experienced an unusually sudden and strong lake-level decline in the first half of 2019, leaving Lake Metzabok (maximum depth ∼25 m) completely dry and Lake Tzibaná (depth ∼70 m) with a water level decreased by approx. 15 m. Before this event, during a lake-level high stand in March 2018, we collected water-borne seismic data with a sub-bottom profiler (SBP) and transient electromagnetic (TEM) data with a newly developed floating single-loop configuration. In October 2019, after the sudden drainage event, we took advantage of this unique situation and carried out complementary measurements directly on the exposed lake floor of Lakes Metzabok and Tzibaná. During this second campaign, we collected time-domain induced polarization (TDIP) and seismic refraction tomography (SRT) data. By integrating the multi-methodological data set, we (1) identify 5–6 m thick, likely undisturbed sediment sequences on the bottom of both lakes, which are suitable for future paleoenvironmental drilling campaigns, (2) develop a comprehensive geological model implying a strong interconnectivity between surface water and karst aquifer, and (3) evaluate the potential of the applied geophysical approach for the reconnaissance of the geological situation of karst lakes. This methodological evaluation reveals that under the given circumstances, (i) SBP and TDIP phase images consistently resolve the thickness of the fine-grained lacustrine sediments covering the lake floor, (ii) TEM and TDIP resistivity images consistently detect the upper limit of the limestone bedrock and the geometry of fluvial deposits of a river delta, and (iii) TDIP and SRT images suggest the existence of a layer that separates the lacustrine sediments from the limestone bedrock and consists of collapse debris mixed with lacustrine sediments. Our results show that the combination of seismic methods, which are most widely used for lake-bottom reconnaissance, with resistivity-based methods such as TEM and TDIP can significantly improve the interpretation by resolving geological units or bedrock heterogeneities, which are not visible from seismic data. Only the use of complementary methods provides sufficient information to develop comprehensive geological models of such complex karst environment

Charakterisierung von Datenfehlern in der geoelektrischen Bildgebung auf Basis einer Analyse des gemessenen Spannungssignals.

Zusammenfassung in deutscher SpracheAbweichender Titel nach Übersetzung der Verfasserin/des VerfassersKürzlich erschienene Studien betonen die gewissenhafte Prozessierung von Daten der Induzierten Polarisation (IP) Bildgebungsmethode. Insbesondere Bildgebungsergebnisse, die auf einer detaillierten Beschreibung des Datenfehlers basieren, zeigen einen stärkeren Kontrast in den elektrischen Eigenschaften und erlauben eine verlässliche Korrelation mit den Strukturen im Untergrund. Eine weit verbreitet Methode zur Beschreibung von systematischen und zufälligen Datenfehlern ist die Analyse der Abweichung zwischen Messungen, die in Normal- und Reziprokkonfiguration gemessen wurden. Für große Messkampagnen (eine große Anzahl an Messprofilen), sowie Monitoringanwendungen ist die Methode jedoch nur eingeschränkt anzuwenden, da die Messungen in Reziprokkonfiguration einen zusätzlich Zeitaufwand bedeuten, der nicht immer vertretbar ist. Diese Masterarbeit beschreibt daher eine neue Datenprozessierungmethode, die auf einer Analyse, der im Zeitbereich gemessenen Abklingkurve des Spannungssignals basiert und keine zusätzliche Messung in Reziprokkonfiguration voraussetzt. Die Methode erlaubt eine zuverlässige Identifikation von systematische Messfehlern und die Beschreibung von zufälligen Datenfehlern. Ein Vergleich von Bildgebungsergebnissen, auf Basis der Normal-Reziprok und der hier vorgestellten Methode, zeigt konsistente Ergebnisse und demonstriert die Anwendbarkeit und Genauigkeit der hier präsentierten Methode.Recent studies have demonstrated the advantages of a careful processing of induced polarization (IP) imaging datasets. In particular, inversion results based on a detailed quantification of data-error have shown the possibility to solve for electrical images with enhanced contrasts and a reliable correlation with subsurface structures and processes, as required for quantitative applications of IP imaging. The analysis of the discrepancy between normal and reciprocal measurements has been established as a suitable method to assess data quality in electrical imaging and the parametrization of error models. However, exploration surveys at extensive areas, or monitoring applications, require of reduced acquisition times hindering the collection of reciprocal measurements. Therefore, this thesis presents an alternative methodology to quantify data error in time-domain IP (TDIP) imaging measurements based on the analysis of the recorded IP decay curve. The "Decay Curve Analysis" (DCA) described here does not require the collection of reciprocal measurements, but provides information about data-error required for the identification of outliers, as well as the quantification of error parameters for the inversion of TDIP imaging datasets. Comparison of the error parameters and imaging results following the DCA analysis and conventional normal-reciprocal analysis revealed consistent results, demonstrating the accuracy of the approach.9