91 research outputs found
Gravity as a tool to improve the hydrologic mass budget in karstic areas
Monitoring the water movements in karstic areas is a fundamental but challenging task due to the complexity of the drainage system and the difficulty in deploying a network of observations. Gravimetry offers a valid complement to classical hydrologic measurements in order to characterize such systems in which the recharge process causes temporarily accumulation of large water volumes in the voids of the epi-phreatic system. We show an innovative integration of gravimetric and hydrologic observations that constrains a hydrodynamic model of the Škocjan cave system (Slovenia). We demonstrate how the inclusion of gravity observations improves water mass budget estimates for the Škocjan area based on hydrological observations only. Finally, the detectability of water storage variations in other karstic contexts is discussed with respect to the noise performances of spring and super-conducting gravimeters
Progression of myopathology in Kearns-Sayre syndrome
We report on the progression of myopathology by comparing two biopsies from a patient with a Kearns-Sayre-Syndrome. The first biopsy was taken in 1979 and showed 10% ragged-red fibers. Myopathic changes were slight including internal nuclei and fiber splitting in 10% of the fibers. Electron microscopy revealed typical mitochondrial abnormalities with regard to number and shape. In 1989 a second biopsy was performed for an extended analysis of mitochondrial DNA. This time less than 5% of all fibers were ragged-red. Severe myopathic changes could be detected which so far has rarely been reported in mitochondrial cytopathy
The 6 May 1976 Friuli earthquake: re-evaluating and consolidating
The aim of this paper is to propose the creation, in terms of European Macroseismic
Scale (EMS-98), of the entire macroseismic fi eld of the 6 May 1976 Friuli earthquake.
Only forty odd years have passed, and nothwithsatnding that there is a huge quantity
of existing data, it was still disturbing to fi nd that much of the original data are missing
and probably lost forever Efforts have therefore been made to fi nd additional and
still unknown primary data. For the majority of the collected national data sets, a reevaluation
was then possible. This study presents the comprehensive macroseismic
data set for 14 European countries. It is, to our knowledge, one of the largest European
data sets, consisting of 3423 intensity data points (IDPs). The earthquake was felt from
Rome to the Baltic Sea, and from Belgium to Warsaw. The maximum intensity 10
EMS-98 was reached in eight localities in Friuli (Italy). Compared to previous studies,
the Imax values have changed from country to country, in some cases being lowered due
to methodological differences, but in the case of three among the most hit countries,
Imax is now higher than in the previous studies, mainly due to the new data.Published417-4444T. Sismicità dell'ItaliaJCR Journa
Editorial note for the Geodesy and Geodynamics journal special issue Contemporary Research in Geodynamics and Earth Tides : An account of the 18th Geodynamics and Earth Tides Symposium 2016, Trieste, Italy
This volume aims at conveying the rich and interdisciplinary topics discussed at the 18th Geodynamics and Earth Tides Symposium, Trieste, 2016. For seventeen times the gathering was named
the Earth Tides Symposium, when giving tribute to the evolution of the observed signals, the term geodynamics was added to the title.The present volume aims at a full coverage of the Symposium by
including the entire list of abstracts that were presented either as oral or poster presentation
A first Alps - dedicated gravity data set - introduction and status of the AlpArray gravity field activities
In this contribution, activities of the AlpArray Gravity Research Group (AAGRG) are introduced. Since 2018, this
group in the frame of the AlpArray project (http://www.alparray.ethz.ch/en/home/) prepares gravity and other data
sets to support multidisciplinary goals of the project. It is focused on the mantle, plate and surface processes in the Alps-Apennines-Carpathians-Dinarides orogenic system.
In 2018, the AAGRG set up its own methodology guidelines and assembled available land-gravity data and
digital elevation model (DEM) data from all the participating countries. Our presentation targets especially three
goals: 1) to introduce AAGRG activities as an integral part of the AlpArray project for studying Alpine orogeny \u2013 a
goal that by definition requires international cooperation, 2) to review the input data and the works accomplished so
far, and, 3) to discuss the steps to be taken to produce detailed gravity maps of the region \u2013 the first Alps-dedicated
gravity field data set. We plan to prepare gravity grids in a homogeneous processing approach of either 2x2 km or
4x4 km resolution, depending on the coverage and data quality. The final data sets will be made public in late 2019.
A special emphasis is put on the calculation of the Bouguer anomaly using ellipsoidal rather tha normal
heights. For calculating topographic effects the preference is given to local DEMs, where available, as they often
provide higher quality and spatial resolutions. The public gravity data sets are evaluated with the high-resolution
geopotential models like EIGEN-6C4 or EGM2008 \u2013 a useful means for identifying biases in the data coming
from various countries and campaigns
A ground based gravity network for monitoring water mass movements in the Classical Karst region
The Classical Karst is a limestone plateau stretching between Italy and Slovenia over an area of about 600km2.The aquifer of Classical Karst contains a complex network of conduits, shafts and large voids that are fed by theautogenic recharge and allogenic input of the Reka River. The Reka River sinks underground in the \u160kocjan Cavesand continues its underground flow for almost 40km until it reaches the Adriatic Sea at the Timavo Springs. Theriver shows high discharge variations; with minimal discharge below 0.3 m3/s and maximal discharge reachingover 350 m3/s. As the conduit system cannot efficiently drain large discharge, huge water masses are stored inthe epiphreatic voids of the aquifer during flood events. \u160kocjan Caves present such storage, where a vast amountof water is temporary stored during intense rain. Further evidences of the impressive water movements in thissystem could be found in the geodetic time-series recorded by the Grotta Gigante horizontal pendulums, whichshow deformation transients during Reka flood events.
Gravimetry could be a useful tool to obtain local mass balances of such complex system, contributing together withthe other classical hydrologic prospections in depicting the water dynamics in this karstic environment. In additionto this gravimetry represents the ideal completion to the already set up geodetic instrumentation in the ClassicalKarst region.
In the last year, we installed two continuous recording gravity stations, near the \u160kocjan caves and inside the GrottaGigante cave. The \u160kocjan caves serve as a test site because the cave geometry and the hydraulic system here arewell known. The Grotta Gigante site offers a quiet place and long term geodetic time-series but on the other hand,the hydrodynamics here are less clear.
In this contribution, we present the simulations in support to the placement of the instruments and the first analysisconducted on the observed gravity time-series. For the \u160kocjan caves our simulations estimate that this mass accu-mulation could generate gravity signals up to 30 microGal for extreme events with peak discharge over 250m3/slasting for 1-1.5 days, accumulating over 35 106m3of water. The recorded data in \u160kocjan supports our simula-tions: a prominent peak up to 5 microGal of amplitude was recorded during a 14 106m3flood event on October2018.
We believe that the Classical Karst represents an interesting study case for both the geodetic and hydrologic com-munities; the \u160kocjan cave offers a natural laboratory to optimally assess the contribution of gravimetry as a toolfor monitoring underground fluid mass movements
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