Search results for "Borehole"
showing 10 items of 44 documents
Aseismic strain episodes at Campi Flegrei Caldera, Italy
2021
Since 2004 a research project has been developed to monitor subsurface deformation of Italian volcanoes using borehole strainmeters and long-baseline tiltmeters. Six Sacks-Evertson dilatometers were installed around Campi Flegrei caldera and Vesuvius during 2004–2005 (Scarpa et al., 2007), and in 2008 these instruments were supplemented by two arrays of 28–280 m long water-tube tiltmeters in underground tunnels. Relevant strainmeter and tiltmeter data have been collected and analysed from the instruments installed near Campi Flegrei caldera during the recent unrest episodes. In the period 2004–2005 strain, tilt and GPS data from Campi Flegrei indicate the onset of surface deformation that a…
Mapping of large-scale diapir structures at the paleo-ice tongue bed in western Latvia from geophysical investigations and borehole data
2022
Abstract This study comprises the investigation of the complex and deformed Late Pleistocene sedimentary sequence in western Latvia composed of sandy sediments that are protruded by large-scale clayey silt diapirs and covered by glaciotectonically disturbed discontinuous patches of the Late Weichselian till. We use detailed measurements by ground-penetrating radar (GPR) and electrical resistivity tomography (ERT) combined with borehole data and sedimentological investigations at the Baltic Sea cliffs to map and characterize the large-scale deformation structures and discontinuous till patches. We distinguish the intriguing and previously not detected characteristics of the spatial distribut…
Continental late Pliocene paleoclimatic history recorded in the Bresse Basin (France)
1992
International audience; We present results to show that the Beaune P & C borehole, cored in the Bresse Basin (France), records late Pliocene climatic variations. Pollen analysis allows precise correlations with northern and southern European stratigraphies. Using Kukla et al.'s (1981) climate index, we show that cold climate phases occur during the Brunssumian, at around 3.2, 3.6 and 5.2 Myr B.P., respectively, in agreement with Atlantic core results. The onset of a general cooling trend is felt early in the Reuverian, at about 3 Myr B.P. which corresponds to the end of a warm event characterized by high percentages of oak. This is followed by minor climatic pulses of increasing magnitude s…
A solar assisted seasonal borehole thermal energy system for a non-residential building in the Mediterranean area
2019
Abstract Solar heating and cooling systems are reliable and feasible solutions among renewable energy technologies. Indeed, solar thermal devices help reduce primary energy consumption and can reduce electricity demand, thus representing one of the best options for satisfying heating and/or cooling energy supply. The Borehole Thermal Energy Storage (BTES) represents one of the best promising option among the various storage technologies, because the size of the storage can be easily extended by drilling additional boreholes and simply connecting the pipes to the existing boreholes; the overall energy efficiency of this system is about 40–60%. In this paper, the authors present an applicatio…
Thermal response test analysis for U-pipe vertical borehole heat exchangers under groundwater flow conditions
2021
[EN] Conventional models used in the analysis of thermal response test data only consider conduction as heat transfer mechanism. In cases where presence of groundwater is detected, convection heat transmission plays an important role, so its influence must be determined in the calculation of the effective thermal conductivity, usually overestimated in these situations, increasing its value the higher the power injected and the time elapsed. In this work, based on the data collected in a borehole located at UPV (Valencia) in which have been carried out three thermal response tests with different characteristics, has been implemented a variation of the finite line source model introducing an …
Energy-saving potential of ground source multiple chillers in simple and hybrid configurations for Mediterranean climates
2022
Air conditioning accounts for a large share of energy usage in residential and tertiary sectors. Renewable energy technologies offer promising solutions to reduce the environmental impacts of meeting buildings’ energy loads. The possibility of using the soil as a thermal reservoir for heating and cooling systems has gained growing attention in the last decade due to its high potential for energy saving. In this paper, the benefits achievable using ground source chillers for air conditioning in an office building located in Southern Italy are discussed. A multiple chillers system coupled with a borehole heat exchanger is investigated and compared to conventional air-cooled and water-cooled s…
OSL dating of Middle Weichselian age shallow basin sediments in Western Latvia, Eastern Baltic
2012
Abstract This paper presents the results of the first attempt to date the Quaternary sediments of western Latvia in the southeast Baltic region, using luminescence. The analyses have been carried out on sandy sediments of the Jurkalne Formation that are located between upper and lower Scandinavian sourced tills. Previous publications on the origin of the Quaternary sediments in the region are reviewed and it is found that there are a wide range of explanations for their processes of formation and their age of formation. It is concluded that although the sandy sediments were deposited in freshwater environment although they contain both marine and freshwater fauna and flora, a property that …
Characterization of major discontinuities from borehole cores of the black consolidated marl formation of Draix (French Alps)
2012
A quantitative description of rock discontinuities present in subsurface cores that were drilled (down to 20 m) in the marls of the Laval and Moulin catchments near Draix (France) is presented. Three kinds of discontinuities are studied: those fully open, those open but filled with clay rich material and those sealed with calcite. With a laser profiler, the topography of facing sides of typical discontinuities was measured with a normal resolution of 1 µm. The probability distribution of the elevation of each surface are obtained and shown to be normal. Possible self-affine scaling invariance of the topography were explored. The mineralogical content of an interface between the marl bulk an…
South Pole glacial climate reconstruction from multi-borehole laser particulate stratigraphy
2013
AbstractThe IceCube Neutrino Observatory and its prototype, AMANDA, were built in South Pole ice, using powerful hot-water drills to cleanly bore>100 holes to depths up to 2500 m. The construction of these particle physics detectors provided a unique opportunity to examine the deep ice sheet using a variety of novel techniques. We made high-resolution particulate profiles with a laser dust logger in eight of the boreholes during detector commissioning between 2004 and 2010. The South Pole laser logs are among the most clearly resolved measurements of Antarctic dust strata during the last glacial period and can be used to reconstruct paleoclimate records in exceptional detail. Here we use…
Application of a new wireless instrument to characterize thermal properties of ground coupled heat exchangers
2010
Abstract In this work, we report the design and laboratory test of a new instrument to measure the temperature of the heat transfer fluid along the borehole exchanger (BHE) by autonomous wireless sensor. The instrument consists of a device, which inserts and extracts miniaturized wireless sensors in the borehole with a mechanical subsystem, composed by a circulating pump and two valves. This device transmits to the sensors the acquisition configuration, and downloads the temperature data measured by the sensor along its way through the borehole heat exchanger. Each sensor is included in a sphere of 25 mm diameter and contains a transceiver, a microcontroller, a temperature sensor and a powe…