TALOS Dome Migration: Preliminary Results

Ice divide-dome migration is a key parameter in mass balance studies and in the interpretation of ice cores. The stability of the dome and position of the ice divide must be known to accurately interpret ice core records and to complete mass balance studies. Models of depth-age relationships for deep ice cores are sensitive to migration of the dome position (Anandakrishnan et al., 1994). The evolution of an ice divide is driven by the accumulation-rate history, its spatial pattern and conditions at ice-sheet boundaries (e.g. Frezzotti et al., 2004; Hindmarsh, 1996; Nereson et al., 1998). Ice divide migration is also important in determining the input parameter of large Antarctic drainage basins. Due to the very low slope (less than a decimetre per km) of East Antarctic domes and to surface morphology (e.g. sastrugi), it is very difficult to determine the summit point of a dome and its migration in time. In 2004 a new ice coring project, TALDICE (Talos Dome Ice Core Project), started at TD to recover 1550 m of ice spanning the last 120 000 years (Frezzotti et al., 2004). This paper discusses preliminary findings on the present and past morphology of Talos Dome based on detailed snow accumulation data, radar-derived isochrons and ice velocity measurements in the last 10 years

Snow Accumulation in the Talos Dome Area: Preliminary Results

Determining snow accumulation is one of the principal challenges in mass balance studies and in the interpretation of ice core records. Accurate knowledge of the spatial distribution of snow accumulation is fundamental for understanding the present mass balance and its implication on sea level change, for reliable numerical simulation of past and future ice sheet dynamics, and for creating atmospheric climate models. Depth-age models for deep ice cores require knowledge of the temporal variability of snow accumulation. Accumulation of snow principally results from precipitation of snow and its redistribution/ablation by wind at the surface (Frezzotti et al., 2004a). Chemical and isotopic analysis of ice cores reveals seasonal and annual signals. However, these signals may not be representative of annual snow accumulation or of the annual chemical/isotopic composition of snow. Talos Dome (TD, 72°48’S; 159°06’E, 2316 m, T -41.0 °C) is an ice dome on the edge of the East Antarctic plateau, about 290 km from the Southern Ocean and 250 km from the Ross Sea (Fig. 1). An ice core is currently being drilled at this site (Frezzotti et al., 2004b) within the framework of the Talos Dome Ice Core Project (TALDICE). In order to provide detailed information on the temporal and spatial variability of snow accumulation, research was conducted at Talos Dome and along a North-South transect (GV7-GV5-TD-31DPT) in the framework of the ITASE programme. The 400 km-long transect follows the ice divide from the Southern Ocean to Talos Dome, and then continues in a southward direction towards Taylor Dome. Stake network measurements, ice core analysis and snow radar surveys along the transect have provided detailed information for reconstructing the temporal (annual) and spatial (meter scale) variability of snow accumulation over the last 200 years at the km scale

Fast geophysical prospecting applied to archaeology: results at «Villa ai Cavallacci» (Albano Laziale, Rome) site

The present essay is the result of a cooperative work between geophysicists and archaeologists in which the authors carried out an integrated geophysical prospecting in an archaeological site near Rome. This paper describes the methodology and the results of a geophysical survey carried out on Villa ai Cavallacci, an ancient roman building in Albano Laziale (Rome) discovered in the late seventies. It is often possible to obtain very important results planning a fast geophysical survey opportunely; within this framework (due to the fact that an archaeological excavation was planned in a short time), an integrated geophysical techniques survey (GPR, magnetic, and geoelectric tomography) has been carried out on the areas indicated by the archaeologists. Even if the described geophysical survey should be considered only a first step analysis, the data pointed out some very interesting features confirmed by the excavation

Location of a new ice core site at Talos Dome (East Antarctica)

In the frame of glaciology and palaeoclimate research, Talos Dome (72°48lS; 159°06lE), an ice dome on the East Antarctic plateau, represents the new selected site for a new deep ice core drilling. The increasing interest in this region is due to the fact that the ice accumulation is higher here than in other domes in East Antarctica. A new deep drilling in this site could give important information about the climate changes near the coast. Previous papers showed that the dome summit is situated above a sloped bedrock. A new position on a relatively flat bedrock 5-6 km far from here in the SE direction was defined as a possible new ice core site for an European (Italy, France, Swiss and United Kingdom) drilling project named as TALDICE (TALos Dome Ice Core Project). This point, named as ID1 (159°11l00mE; 72°49l40mS), became the centre of the Radio Echo Sounding (RES) flight plan during the 2003 Italian Antarctic expedition, with the aim of confirming the new drilling site choice. In this paper 2001 and 2003 RES data sets have been used to draw a better resolution of ice thickness, bottom morphology and internal layering of a restricted area around the dome. Based on the final results, point ID1 has been confirmed as the new coring site. Finally, the preliminary operations about the installation of the summer ice core camp (TALDICE) at ID1 site carried out during the XX Italian Antarctic expedition (November 2004-December 2005) are briefly described

Evidence for Possible New Subglacial Lakes along a Radar Transect Crossing the Belgica Highlands and the Concordia Trench

Subglacial lakes are of great interest to the scientific community, and about 190 lakes have been identified in Antarctica and catalogued (Siegert et al., 2005; Cafarella et al., 2006; Popov & Masolov, 2007). We report on the possible existence of 5 new subglacial lakes in the area between the Belgica HighLands and the Concordia Trench. Analysis of radar data collected during the 2003 Antarctic field survey reveals particularly strong radar echoes coming from the subglacial interface. As radar surveys are only one of the methods used to identify subglacial lakes, the presence of these 5 new lakes must be discussed and confirmed through other geophysical investigations

A NEW BRANCH of the ANIO NOVUS AQUEDUCT (ROME, ITALY) REVEALED by ARCHAEOLOGY and GEOPHYSICS

The area south-east of Rome is characterised by the presence of several roman aqueducts which brought water to the eternal city from the Apennine and Alban Hills springs. In the last 40 years, several pieces of evidence about these aqueducts were acquired during the realisation of archaeological test trenches before building activities. In 2019, a small branch of a subterranean aqueduct unknown to the Latin sources was unearthed in Via dei Sette Metri. Here we show that this aqueduct is a lateral branch of the Anio Novus, a major imperial aqueduct built between 38 and 52 CE. To achieve this result, we employed detailed photogrammetric restitution of the new aqueduct and an integrated geophysical survey focused in the area where the Anio Novus was supposed to pass. Electrical Resistivity Tomography (ERT) and Ground Penetrating Radar (GPR) methods were used to reconstruct aqueduct paths and their relative heights. Different light conditions were tested during the picture acquisition step to determine the best practice in the photogrammetric restitution. The results obtained in this study confirmed the great effectiveness of the integration between geophysical investigation methods and the modern archaeology approach in detecting buried ancient structures

A synthesis of the Antarctic surface mass balance during the last 800 yr

Global climate models suggest that Antarctic snowfall should increase in a warming climate and mitigate rises in the sea level. Several processes affect surface mass balance (SMB), introducing large uncertainties in past, present and future ice sheet mass balance. To provide an extended perspective on the past SMB of Antarctica, we used 67 firn/ice core records to reconstruct the temporal variability in the SMB over the past 800 yr and, in greater detail, over the last 200 yr. <br><br> Our SMB reconstructions indicate that the SMB changes over most of Antarctica are statistically negligible and that the current SMB is not exceptionally high compared to the last 800 yr. High-accumulation periods have occurred in the past, specifically during the 1370s and 1610s. However, a clear increase in accumulation of more than 10% has occurred in high SMB coastal regions and over the highest part of the East Antarctic ice divide since the 1960s. To explain the differences in behaviour between the coastal/ice divide sites and the rest of Antarctica, we suggest that a higher frequency of blocking anticyclones increases the precipitation at coastal sites, leading to the advection of moist air in the highest areas, whereas blowing snow and/or erosion have significant negative impacts on the SMB at windy sites. Eight hundred years of stacked records of the SMB mimic the total solar irradiance during the 13th and 18th centuries. The link between those two variables is probably indirect and linked to a teleconnection in atmospheric circulation that forces complex feedback between the tropical Pacific and Antarctica via the generation and propagation of a large-scale atmospheric wave train

Radio echo sounding data analysis of the Shackleton Ice Shelf

In this study, our initial results are presented for the interpretation of the radio echo sounding data collected over the Shackleton Ice Shelf and adjacent ice sheet (East Antarctica) during the 2003/2004 Australian- Italian expedition. The Shackleton Ice Shelf is one of the larger ice shelves of the East Antarctic Ice Sheet. The radar survey provided data relating to ice thickness and bed morphology of the outlet glaciers, and thickness of their floating portions. The glacier grounding lines were determined by assessment of the basal echo characters. The information derived is compared with data from the BEDMAP database and from other sources

18F-FDG-PET/CT imaging in cardiac tumors: illustrative clinical cases and review of the literature.

Cardiac tumors are a very rare condition. Mostly, they are benign tumors (75%), with myxomas being the most frequent. The remaining 25% are malignant; either primary malignant sarcoma or secondary metastases. Given the small number of cases reported and the lack of prospective and randomized clinical trials, the level of evidence for the optimal multimodal treatment of primary cardiac sarcomas is very low and the optimal imaging diagnostic workup is not well established. In particular, 18F-FDG-PET/CT is not yet included in routine diagnosis of cardiac masses. Here, we report four illustrative clinical cases and a review of the literature on the current available data on the role of 18F-fluorodeoxyglucose PET/CT imaging in cardiac tumors