Preliminary Report: Evaluating the Potential of Archaeogeophysical Surveying on Viking Age and Medieval Sites in Greenland, 2 – 16 August, 2010

The primary goal of this research is to begin to overcome biases in the Greenlandic Norse archaeological record. Assessing the establishment dates and organization of Norse sites in Greenland is difficult because substantial cultural deposits can be hidden under deep windblown sand deposits as well as later occupations. Shallow geophysical methods were used to help recover information on the nature, extent and depth of subsurface cultural deposits. Assessing these site characteristics is a first step in overcoming the bias towards the later, the larger, and the more visible sites in the archaeological record. Norse Greenland presents a relatively visible medieval landscape with many ruins preserved on the surface. Survey archaeologists have taken advantage of these conditions to do comprehensive surveys of Norse settlements producing inventories of farm buildings and settlements (Guldager, et al. 2002; Keller 1990). Coring surveys and excavation at known sites have demonstrated that some sites are buried under significant aeolian deposits and that areas within many other sites can be deep and contain ruins that are not visible on the surface. In many cases Viking Age deposits cannot be accessed by archaeological excavation, as this would damage later occupational phases. In these cases, application of archeogeophysics may be the only way to assess this unique cultural history. The identification, characterization, and dating of these subsurface architectural remains are critical to systematic survey programs and to the production of regional settlement patterns and chronologies that can help explain the ecological and political dynamics of Norse colonization, land use, and the eventual demise of Norse Greenland. Over the past 10 years the Skagafjörður Archaeological Settlement Survey (SASS) has developed an intensive subsurface survey protocol to systematically recover, date, and characterize Viking Age landscapes in Iceland. While we believe the SASS subsurface protocol can be effective in Greenland there are many questions that must be resolved before any wide-scale application of the methods can be developed. The project set out to address two basic questions: (1) what is the actual subsurface record at Norse sites, and (2) which methods work best and how are they most effectively employed? In this initial investigation, we tested and adapted this protocol to conditions in Greenland. We hope that the preliminary test of these methods will significantly expand the range of sites and periods accessible to researchers working in Greenland and allow for new questions regarding the long-term political and environmental histories of the region. The successful integration of archaeogeophysics with archaeological survey and excavation will result in a more holistic approach to the preservation of Norse archaeological sites in Greenland. These sites suffer from increased modern impacts resulting from mineral exploitation, sheep farming, and tourism. Additionally, there is now total summer sub-surface thaw and conditions that were once ideal for preserving organic remains are now deteriorating, especially in well-drained areas. In the coming years the Greenland National Museum will begin a program of scheduling and protecting some of these sites. We believe that the application of archaeogeophysics could be a great asset in determining which sites are in danger and worthy of preservation

Results of Archaeogeophysical Surveying at the Great Friends Meeting House in Newport, Rhode Island

Archaeogeophysical surveys were carried out in October 2010 over a 30 x 50 m grid that was established immediately to the north and west of the north end of the Great Friends Meeting House (GFMH) in Newport, RI. The surveys were conducted using a Geonics EM-38 RT ground conductivity meter and a Malå X3M Ground Penetrating Radar (GPR) system that was equipped with 500 and 800 MHz antennas. In addition, a resistance survey was performed over a much smaller central area using a Geoscan RM15 resistance meter. From this work three types of geophysical anomalies have been identified: those associated with individual features, structures, and graves. There may be one large structure to the north of the GFMH with a similar alignment. Forty-two anomalies were identified that are consistent with graves. There are many more anomalies that have not been specifically interpreted as graves because they did not meet enough of our criteria but may indeed be graves. We recommend that additional archaeogeophysical surveys be performed as well as a series of follow-up excavations to ground truth the interpretations

Egg on Hegranes: Geophysical Prospection, Coring, & Test Excavations—Report 2016

This report describes the 2016 archaeological work at the farm of Egg is in the southernmost part of Hegranes, North Iceland

Combined Ground Deformation Study Of Broader Area Of Patras Gulf (W. Greece) Using PSI-WAP, DGPS And Seismicity Analyses

Long-term ground deformation monitoring using the Persistent Scatterer Interferometry Wide Area Product (PSI-WAP) technique for the period 1992-2003, combined with Differential GPS measurements and seismicity analysis has provided useful information about the tectonic motions of the tectonically complex area of Patras Gulf (Western Greece), and lead to new insights on the geotectonic regime of this region. Descending ERS radar images were used to compile the PSI-WAP product that has been calibrated using the absolute velocity field of available GPS stations in the area. It has been found that the deformation of the southern part of Patras Gulf near the coastline has been characterized by considerable subsidence (>-5mm/yr), where unconsolidated sediments usually prevail, compared to the northern part of the gulf. Significant subsidence has also been identified in areas along the down-throw side of possible faults, as well as areas where extensive ground water pumping has occurred for irrigation. These results correlate well with local GPS and seismicity data

A Bayesian approach to linking archaeological, paleoenvironmental and documentary datasets relating to the settlement of Iceland (Landnám)

YesIcelandic settlement (Landnám) period farmsteads offer opportunities to explore the nature and timing of anthropogenic activities and environmental impacts of the first Holocene farming communities. We employ Bayesian statistical modelling of archaeological, paleoenvironmental and documentary datasets to present a framework for improving chronological robustness of archaeological events. Specifically, we discuss events relevant to the farm Hrísbrú, an initial and complex settlement site in southwest Iceland. We demonstrate that tephra layers are key in constraining reliable chronologies, especially when combined with related datasets and treated in a Bayesian framework. The work presented here confirms earlier interpretations of the chronology of the site while providing increased confidence in the robustness of the chronology. Most importantly, integrated modelling of AMS radiocarbon dates on Hordeum vulgare grains, palynological data, documented evidence from textual records and typologically diagnostic artefacts yield increased dating reliability. The analysis has also shown that AMS radiocarbon dates on bone collagen need further scrutiny. Specifically for the Hrísbrú farm, first anthropogenic footprint palynomorph taxa are estimated to around AD 830–881 (at 95.4% confidence level), most likely before the tephra fall out of AD 877 ± 1 (the Landnám tephra layer), demonstrating the use of arable fields before the first known structures were built at Hrísbrú (AD 874–951) and prior to the conventionally accepted date of the settlement of Iceland. Finally, we highlight the importance of considering multidisciplinary factors for other archaeological and paleoecological studies of early farming communities of previously uninhabited island areas

Unconfined Aquifer Flow Theory - from Dupuit to present

Analytic and semi-analytic solution are often used by researchers and practicioners to estimate aquifer parameters from unconfined aquifer pumping tests. The non-linearities associated with unconfined (i.e., water table) aquifer tests makes their analysis more complex than confined tests. Although analytical solutions for unconfined flow began in the mid-1800s with Dupuit, Thiem was possibly the first to use them to estimate aquifer parameters from pumping tests in the early 1900s. In the 1950s, Boulton developed the first transient well test solution specialized to unconfined flow. By the 1970s Neuman had developed solutions considering both primary transient storage mechanisms (confined storage and delayed yield) without non-physical fitting parameters. In the last decade, research into developing unconfined aquifer test solutions has mostly focused on explicitly coupling the aquifer with the linearized vadose zone. Despite the many advanced solution methods available, there still exists a need for realism to accurately simulate real-world aquifer tests

A late Wisconsin (32–10k cal a BP) history of pluvials, droughts and vegetation in the Pacific south-west United States (Lake Elsinore, CA)

Continuous, sub-centennially resolved, paleo terrestrial records are rare from arid environments such as the Pacific south-west United States. Here, we present a multi-decadal to centennial resolution sediment core (Lake Elsinore, CA) to reconstruct late Wisconsin pluvials, droughts and vegetation. In general, the late Wisconsin is characterized by a wetter and colder climate than during the Holocene. Specifically, conditions between 32.3 and 24.9k cal a BP are characterized by large-amplitude hydrologic and ecologic variability. Highlighting this period is a ∼2000-year glacial mega-drought (27.6–25.7k cal a BP) during which the lake shallowed (3.2–4.5 m depth). This period is approximately coeval with a Lake Manix regression and an increase in xeric vegetation in the San Bernardino Mountains (Baldwin Lake). The Local Last Glacial Maximum (LLGM) is bracketed between 23.3 and 19.7k cal a BP − a ∼3000-year interval characterized by reduced run-off (relative to the glacial), colder conditions and vegetative stability. Maximum sustained wetness follows the LLGM, beginning at 19.7 and peaking by 14.4k cal a BP. A two-step decrease in runoff characterizes the Lateglacial to Holocene transition; however, the vegetation change is more complex, particularly at the beginning of the Younger Dryas chronozone. By 12.6–12.4k cal a BP, the climate achieved near Holocene conditions

Digital Stereotomics: L'apparecchiatura elicoidale dei ponti obliqui. "Ponte a Grisignano di Zocco"

Il lavoro svolto nell’ambito di questa tesi è sostanzialmente diviso in tre parti; una prima parte affronta l’interpretazione geometrica e costruttiva di un sistema stereotomico complesso (l’apparecchiatura elicoidale dei ponti obliqui).La seconda parte ha riguardato uno studio relativo alle differenti fasi del processo della fotomodellazione architettonica usato per il rilievo e la restituzione del caso studio. La terza parte affronta le verifiche geometrica-costruttiva e sismic