Search results for "Geochemistry"

Fragmentation during Rock Falls: Two Italian Case Studies of Hard and Soft Rocks

2008

In recent years, rock fall phenomena in Italy have received considerable attention for risk mitigation through in situ observations and experimental data. This paper reports the study conducted at Camaldoli Hill, in the urban area of Naples, and at Monte Pellegrino, Palermo, Italy. The rocks involved are volcanic Neapolitan yellow tuff (NYT) in the former area and dolomitic limestone in the latter. Both rocks, even though with different strength characteristics, have shown a significant tendency towards rock fragmentation during run out. This behavior was first investigated by comparing the volumes of removable blocks on the cliff faces (V 0) and fallen blocks on the slopes (V f). It was as…

Evaporite karst in Italy: A review

2017

none 16 si Although outcropping rarely in Italy, evaporite (gypsum and anhydrite) karst has been described in detail since the early 20th century. Gypsum caves are now known from almost all Italian regions, but are mainly localised along the northern border of the Apennine chain (Emilia Romagna and Marche), Calabria, and Sicily, where the major outcrops occur. Recently, important caves have also been discovered in the underground gypsum mines in Piedmont. During the late 80s and 90s several multidisciplinary studies were carried out in many gypsum areas, resulting in a comprehensive overview, promoting further research in these special karst regions. More recent and detailed studies focused…

Preface to the Special Issue on ‘‘Applications and developments of magnetic resonance techniques in geosciences’’

2011

A PTFE membrane for the in situ extraction of dissolved gases in natural waters: Theory and applications

2005

A new method for extracting dissolved gases in natural waters has been developed and tested, both in the laboratory and in the field. The sampling device consists of a polytetrafluroethylene (PTFE) tube (waterproof and gas permeable) sealed at one end and connected to a glass sample holder at the other end. The device is pre-evacuated and subsequently dipped in water, where the dissolved gases permeate through the PTFE tube until the pressure inside the system reaches equilibrium. A theoretical model describing the time variation in partial gas pressure inside a sampling device has been elaborated, combining the mass balance and "Solution-Diffusion Model" (which describes the gas permeation…

Water-use efficiency and transpiration across European forests during the Anthropocene

2015

Considering the combined effects of CO2 fertilization and climate change drivers on plant physiology leads to a modest increase in simulated European forest transpiration in spite of the effects of CO2-induced stomatal closure. The Earth’s carbon and hydrologic cycles are intimately coupled by gas exchange through plant stomata1,2,3. However, uncertainties in the magnitude4,5,6 and consequences7,8 of the physiological responses9,10 of plants to elevated CO2 in natural environments hinders modelling of terrestrial water cycling and carbon storage11. Here we use annually resolved long-term δ13C tree-ring measurements across a European forest network to reconstruct the physiologically driven r…

The ABCflux database: Arctic-boreal CO2flux observations and ancillary information aggregated to monthly time steps across terrestrial ecosystems

2022

Past efforts to synthesize and quantify the magnitude and change in carbon dioxide (CO2) fluxes in terrestrial ecosystems across the rapidly warming Arctic–boreal zone (ABZ) have provided valuable information but were limited in their geographical and temporal coverage. Furthermore, these efforts have been based on data aggregated over varying time periods, often with only minimal site ancillary data, thus limiting their potential to be used in large-scale carbon budget assessments. To bridge these gaps, we developed a standardized monthly database of Arctic–boreal CO2 fluxes (ABCflux) that aggregates in situ measurements of terrestrial net ecosystem CO2 exchange and its derived partitioned…

Hillslope degradation in representative Italian areas. Just soil erosion risk or opportunity for development?

2018

In recent years, much research have dealt with the impact of human and climate change on the morpho-evolution of Mediterranean catchments characterized by high ecological and cultural value. In this paper, we speculated how humans can influence hillslope degradation by reviewing the relationships between denudation processes and land use changes in some representative areas located in different Italian regions (i.e., Liguria, Tuscany, Basilicata, and Sicily). The selected study cases are characterized by different climatic and geological features, land use, and land management and can be considered indicative of the hillslope degradation issues that affected the Apennines during the last ce…

Chemical-physical parameters, major, minor and trace elements compositions of big karst springs of Greece

2023

This database consists of samples of karst springs collected in Greece and selected on the base of their water flow (> 50 L s-1), over the period from May 2016 to October 2022

Chemical-physical parameters, major, minor and trace elements composition of thermo-mineral groundwaters of Greece

2022

This dataset comprises samples of thermo-mineral waters collected by the same team over the period from October 2004 to March 2020 and analysed in the same laboratory. Samples were collected on the whole territory of Greece.

The Coupled Magmatic and Hydrothermal Systems of the Restless Aluto Caldera, Ethiopia

2020

Seismicity can be used to better understand interactions between magma bodies, hydrothermal systems and their host rocks—key factors influencing volcanic unrest. Here, we use earthquake data to image, for the first time, the seismic velocity structure beneath Aluto, a deforming volcano in the Main Ethiopian Rift. Traveltime tomography is used to jointly relocate seismicity and image 3D P- and S-wave velocity structures and the ratio between them (V P/V S). At depths of 4–9 km, the seismicity maps the top of a large low velocity zone with high V P/V S, which we interpret as a more ductile and melt-bearing region. A shallow (<3 km) hydrothermal system exhibits low seismic velocities and ve…