Mapping of the Buried Yarmouth Roads Wreck, Isle of Wight, UK, using a Chirp Sub-Bottom Profiler

Remains of the 16th-century Yarmouth Roads wreck, buried in sediments, were imaged using high-resolution geophysical techniques. The remains appear as strong reflectors underlain by an acoustic blanking zone, which was used to create maps of the wreck material. Close survey line-spacing allowed the construction of contour maps and hull sections, which revealed that the bow and stern sections are tilted to port at different angles, implying that they are detached. The seismic data have enhanced our understanding of the site beyond what was known from conventional archaeological investigations and confirms that this wreck was once a large carrack.
© 2007 The Authors     

A Simplified Calculation Method for Liquefaction-Induced Settlement of Shallow Foundation

This work was aimed at developing a practical and simple settlement estimation of shallow foundation on liquefiable deposits. The study conducted a centrifuge test, a series of comprehensive numerical analysis, back analysis, equation calibration, and verification with data from not only centrifuge test but also the literature. It finally proposed a quick calculation method based on Meyerhof’s settlement equation (1965). A two-dimensional numerical analysis, named ALID, (Analysis for Liquefaction-induced Deformation), was employed for obtaining settlement of shallow foundations on liquefiable soils with different relative densities under various seismic conditions. Its performance was first verified through a centrifuge test conducted in this study. Then, the developed method based on Meyerhof’s settlement equation was employed, and a new parameter, N_LR, was proposed to present the strength of liquefied soils by replacing N value in the original equation. The N_LR was obtained through back analysis of the numerical results and modified accordingly after comparison with the data from the literature. This paper, finally, demonstrated the practical use of the proposed method involving N_LR by predicting 199 sets of liquefaction-induced settlement of shallow foundation reported in the past, including a latest most liquefaction-induced settlement of a house in 0206 earthquake on February 6, 2016, in Taiwan.     

Archaeological Assessment of Second World War Anti‐Torpedo Close Protection Pontoons in Scapa Flow,Orkney

This paper presents the outcomes of sidescan sonar and archaeological diving surveys in 2015 of two wrecked vessels located off Flotta Island, Orkney, North Scotland. Archival research indicates these are the remains of Anti‐Torpedo Close Protection Pontoons (ATCPP), an experimental protection device used for close protection of naval vessels at anchor in Scapa Flow from attack by aircraft‐launch torpedoes. The pontoons were only in operation in Scapa Flow for 13 months (March 1941–April 1942) and few were brought into service. As such they represent a rare heritage resource, for which very little is known about their operation.     

A Regional Approach to Ancient Urban Studies in Greece Through Multi-Settlement Geophysical Survey

The systematic exploration of large archaeological sites in the Mediterranean has evolved considerably since the “big dig” excavations. Pedestrian field surveying and remote sensing applications, including satellite and airborne image analysis, are now practical and relatively cost-efficient methods of characterizing large and diachronically diverse landscapes on regional scales. However, the use of geophysical techniques as a means for exploring manifold archaeological contexts is still in its infancy. In this paper, we highlight the advantages of archaeological geophysics to conduct regional surveys in the Mediterranean. Through a multi-site geophysical fieldwork campaign to investigate the patterns and dynamics of ancient cities in Greece, we show how geophysics offer new opportunities for characterizing the spatial attributes and regional dynamics of urban landscapes, and, in doing so, we make an argument for its wider adoption on regional survey projects.     

Nanozonation in Dense Cities: Testing a Combined Methodology in Barcelona City (Spain)

Microzonation is widely used in seismic risk evaluations to define the predominant period values, which are usually associated with extended areas of a few hundred meters. However, the representative values corresponding to these areas are obtained from few measurements in each area. Thereby, results are accurate only in the case of depth-dependent soils. However, not detected narrow and sharp lateral changes in soil are potentially the cause of imprecision and could be a source of specific errors. This article aims to present several tests conducted in order to emphasise the importance of accurate selection of points, to underscore the necessity of more precise and detailed evaluations, and to suggest a possible methodology to select the most appropriate data acquisition points. Results highlight the need to divide microzonation areas into smaller zones for a precise evaluation in locations where sudden changes in soil characteristics exist. Therefore, in such sites the requirement of nanozonation appears; defining zones with the same soil response. Distance between vibration measurements could be the main problem for nanozonation; data acquisition in areas with irregular geology can be time consuming when a precise analysis is required. In the most complicated environments or in dense cities, it could even be unfeasible. Consequently, it is necessary to establish a functional methodology to adequately distribute the measurement points throughout the area. On this occasion, three sites in Barcelona city were studied. This city is surrounded by mountains at NW, W, and S, and by the Mediterranean Sea at N and E. As a consequence, the shallow geology is characterized by many paleochannels and streams that are currently buried. These geological structures most likely affect the soil response. Several tests were carried out to determine this dependence. The tests were based on Ground Penetrating Radar (GPR) surveys to define the paleochannels position and on vibration measurements in order to define properly the soil response. The results from both methods were compared to the known geology to accurately define the effect of the shallow geological structures in the predominant period and in the GPR images. Areas with the same geological unit but different materials were identified in the GPR images, allowing the selection of the most appropriate distance between vibration measurements in each place. As a final result, predominant periods that were measured over the same geological unit but over different material showed changes higher than the 40% in short distances. This procedure could improve the soil response maps, including nanozonation.     

Finding a Relatively Flat Archaeological Site with Minimal Ceramics: A Case Study from Iraqi Kurdistan

ABSTRACT

We present a new technique to detect flat archaeological sites with minimal ceramics using an unmanned aerial vehicle that maps surface stone concentrations. Methods deployed include point pattern analysis of stone concentrations and a machine-learning technique using unsupervised classification of visible stone signature qualities, which are used in simple linear regressions to compare with geophysical and ceramic surface survey results of a site in Iraqi Kurdistan. There is a stronger fit (r^2?=?0.77) between surface stone concentrations and architecture identified by geophysical measurement, while surveyed ceramics show a weaker fit to defined architecture (r^2?=?0.31). Surface stone concentrations are potentially a better proxy than ceramics for determining the presence of past settlement in regions where stone was commonly used, sites are relatively flat, and ceramics are found in low concentrations. The methods advanced here can be scaled to wider areas, particularly in mountainous regions, where surface stone features are present.     

Site Classification System and Site Coefficients for Shallow Bedrock Sites in Korea

Recent studies have shown that the site coefficients obtained from site response analyses of Korean soil sites are significantly different from those specified in the current Korean seismic code, especially in the short-period portion of site response. This difference is mainly attributed to the shallow bedrock conditions (bedrock depth usually less than 30 m) in Korea. This study proposes a new site classification system and site coefficients for shallow bedrock sites based on site response analyses of more than 300 sites. The proposed site classification scheme and site coefficients proposed in this study are an improvement over the current seismic code and previous studies.     

Bridging the gap: a terrestrial view of shallow marine sequences and the importance of the transition zone

The shallow shelf area around the coast of the UK contains an important record of maritime and, potentially prehistoric archaeology. Increasingly this area is the focus of anthropogenic activity such as gravel extraction and cable laying in advance of which it is increasingly common practice to investigate the archaeological potential of the sequences/regions. Well structured approaches have been developed for the investigation of maritime wrecks and the latest Prehistoric remains, however the Palaeolithic archaeological potential of these regions is less clear. This is partly due to the depth of burial of archaeological material and the rather more fragmentary nature of the sequences present. Where consideration of the Palaeolithic archaeology has been undertaken, models and presumptions derived from terrestrial situations have been extrapolated across the near shore zone, where often there is no data, and into the maritime area. Within the maritime area these models have been used to interpret seismic data and scarce offshore core data for making regional reconstructions. Here we consider some of the issues in reconstruction and highlight the difficultly in extrapolating between terrestrial and maritime situations without careful investigation in the transition zone. In particular we argue that rather than assuming similarities between patterns of landscape evolution between the on- and off-systems we should anticipate dissimilarity of patterns, missing sequences and different landscape formation processes particularly in those areas of the shallow shelf area formerly occupied by drainage basins during sea level low-stands.     

Location of the Brecourt (Normandy,France) WW2 Howitzer battery using a geoforensic search strategy

The assault on D-day by Easy Company of the 101^st Airborne Corps on a German howitzer battery at Brecourt Manor (Normandy) that was firing upon Utah Beach is a famous action of World War 2. Understanding the firefight and disablement of the guns depends on where the four howitzers and crew were located. Three of the locations are unequivocal, with post-WW2 accounts and the search described here in agreement. One Howitzer position (the northernmost of the four) remains in contention, with two different positions described. A geoforensic search strategy (desktop study, geophysics, excavation) was deployed that shows strong evidence for the location of the debated fourth gun, together with aerial photographic and military tactical evidence for why this fourth Howitzer was moved to a second location close to D-day.     

MOUND BUILDING AT LAKE JACKSON (8LE1), TALLAHASSEE,FLORIDA: NEW INSIGHTS FROM GROUND PENETRATING RADAR

Abstract

The Lake Jackson Mounds site (8LE1), located near Tallahassee, Florida, has long been considered to be a frontier Mississippian center. This assertion is primarily based on elaborate burial goods recovered during salvage excavations in the 1970s. Ground penetrating radar (GPR) on the two largest intact mounds at Lake Jackson revealed new information about their morphology and construction histories. These findings demonstrate that mound-building practices at the site were distinct from earlier, local Woodland mound-building traditions, and more similar to those of other Mississippian centers, such as Etowah and Moundville. Lake Jackson revitalized mound building in the Tallahassee area under the influence of external connections with groups in the Mississippian interaction network. These findings show how mound building was an integral practice for expressing and expanding Mississippian ideologies and rituals. This work also shows the utility of GPR in exploring mounds' morphologies and construction histories.