We propose that the brittle-ductile transition （BDT） controls the seismic cycle. In particular, the movements detected by space geodesy record the steady state deformation in the ductile lower crust, ...whereas the stick-slip behavior of the brittle upper crust is constrained by its larger friction. GPS data allow analyzing the strain rate along active plate boundaries. In all tectonic settings, we propose that earthquakes primarily occur along active fault segments characterized by relative minima of strain rate, segments which are locked or slowly creeping. We discuss regional examples where large earthquakes happened in areas of relative low strain rate. Regardless the tectonic style, the interseismic stress and strain pattern inverts during the coseismic stage. Where a dilated band formed during the interseismic stage, this will be shortened at the coseismic stage, and vice-versa what was previously shortened, it will be dilated. The interseismic energy accumulation and the coseismic expenditure rather depend on the tectonic setting （extensional, contractional, or strike-slip）. The gravitational potential energy dominates along normal faults, whereas the elastic energy prevails for thrust earthquakes and performs work against the gravity force. The energy budget in strike-slip tectonic setting is also primarily due elastic energy. Therefore, precursors may be different as a function of the tectonic setting. In this model, with a given displacement, the magnitude of an earthquake results from the coseismic slip of the deformed volume above the BDT rather than only on the fault length, and it also depends on the fault kinematics.
Computing in ALICE Brun, R.; Buncic, P.; Carminati, F. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2003, Letnik:
502, Številka:
2
Journal Article
Recenzirano
The objective of the offline framework is to reconstruct and analyse the data coming from real interactions. The ALICE Offline framework, AliRoot, has already been used during the production of the ...Technical Design Reports of each detector to optimise their design and it is currently used to evaluate the physics performance of the full ALICE detector.
This paper describes the AliRoot software environment. We wish to put into perspective the main decisions and the organisation of the offline project. First a general description of the ALICE offline framework (AliRoot) is given, starting with a short historical background followed by a description of the simulation, reconstruction and analysis architecture and the organisation of the ALICE offline project. Finally we briefly indicate the main conclusions of our work on AliRoot.
The HAMSTRAD microwave instrument operates at 60 and 183 GHz and measures temperature and water vapor, respectively, from 0- to 10-km altitude with a time resolution of 7 min. The radiometer has been ...successfully deployed at Dome C (Concordia Station), Antarctica (75°06' S, 123°21' E, 3233 m amsl) during the first summertime campaign for 12 days in January-February 2009. The radiometer has been continuously running since January 2010, hosted within a dedicated shelter. We have used the very first set of HAMSTRAD data, recorded when the instrument was outdoors, to assess its potential to sound the troposphere over Dome C, from the planetary boundary layer (PBL) up to the tropopause ( ~ 6 km above surface, ~ 9 km amsl). We have compared the HAMSTRAD measurements to several sets of measurements performed at the Dome-C station or in its vicinity: meteorological radiosondes, in situ PT100 and Humicap sondes along the vertical extent of a 45-m tower, meteorological sensor attached to the HAMSTRAD instrument, and the spaceborne Infrared Atmospheric Sounding Interferometer (IASI) instrument onboard the EUMETSAT MetOp-A satellite in polar orbit. The variability of integrated water vapor (IWV) observed by HAMSTRAD with extremely low values of 0.5 kg ·m -2 was also measured by the radiosondes (very high HAMSTRAD versus radiosonde correlation of 0.98), whereas IASI cloud-free measurements did not reproduce well the HAMSTRAD IWV variation (weak HAMSTRAD versus IASI correlation of 0.58). The measurements of absolute humidity (H 2 O) from HAMSTRAD at Dome C cover a large vertical extent from the surface to about 6 km above surface with a high sensitivity in the free troposphere. The strong diurnal variation of H 2 O observed by the in situ sensors in the PBL is not well detected by the radiometer. In the free troposphere, the HAMSTRAD versus radiosonde H 2 O correlation can reach 0.8-0.9. Around the tropopause, HAMSTRAD shows the same variability as IASI and radiosondes but with a dry bias of 0.01 g ·m -3 . HAMSTRAD tends to show a wetter atmosphere by 0.1-0.3 g ·m -3 compared with radiosondes from the surface to ~ 2-km altitude and a drier atmosphere above by ~ 0.1g ·m -3 . The sensitivity of the temperature profiles from HAMSTRAD is very high in the PBL and in the free troposphere but degrades around the tropopause. The strong diurnal signal measured above the surface by HAMSTRAD (3-6 K) is consistent with all the other in situ data sets. The temporal evolution over the 12-day period in the PBL is also consistent with all other data sets (radiosondes, IASI, in situ sondes, and meteorological sensors). In the free troposphere and around the tropopause, the HAMSTRAD temporal evolution is consistent with that observed by radiosondes and IASI, although a cold bias exists compared with IASI and radiosondes around the tropopause. For heights less than 4 km above surface, HAMSTRAD correlates very well with radiosondes and in situ sensors (correlation better than 0.8) but less well with IASI (0.4). Below the tropopause, the IASI and HAMSTRAD correlation reaches 0.9, whereas above the tropopause, the correlation of IASI and radiosondes with HAMSTRAD is rather low (<; 0.5). Throughout the 12-day period (except on January 23), in the lowermost troposphere for heights less than 500 m above surface, the HAMSTRAD temperature profiles agree with the profiles measured by the radiosondes. From 500 m up to 5 km above the surface, the HAMSTRAD temperature profile has a cold bias from 1 to 5 K compared with the radiosondes, but for some dates (e.g., on January 25 and 29), the HAMSTRAD temperature is very close to the radiosonde temperature. HAMSTRAD generally measures a tropopause lower and warmer than the radiosondes except on some occasions, for instance, on January 23, 30, and 31. In the lower stratosphere, HAMSTRAD measurements of H 2 O and temperature have little sensitivity. Based upon 5-day back trajectory analyses, the great variability of H 2 O and temperature above Dome C as measured by the different instruments from the surface up to the tropopause over the 12-day period can be explained by the origin of air masses. The Dome-C site is found to be under the influence of the oceanic middle latitudes and the Antarctic coastal latitudes, but on some occasions, the air masses originated from the Antarctic continent are associated with colder and drier episodes.
The present analysis deals with one of the most debated aspects of the studies on the upper troposphere/lower stratosphere (UTLS), namely the budget of water vapour (H2O) at the tropical tropopause. ...Within the French project “Multiscale water budget in the upper troposphere and lower stratosphere in the TROpics” (TRO-pico), a global-scale analysis has been set up based on space-borne observations, models and assimilation techniques. The MOCAGE-VALENTINA assimilation tool has been used to assimilate the Aura Microwave Limb Sounder (MLS) version 3.3 H2O measurements within the 316–5 hPa range from August 2011 to March 2013 with an assimilation window of 1 h. Diagnostics based on observations minus analysis and forecast are developed to assess the quality of the assimilated H2O fields. Comparison with an independent source of H2O measurements in the UTLS based on the space-borne Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) observations and with meteorological ARPEGE analyses is also shown. Sensitivity studies of the analysed fields have been performed by (1) considering periods when no MLS measurements are available and (2) using H2O data from another MLS version (4.2). The studies have been performed within three different spaces in time and space coincidences with MLS (hereafter referred to as MLS space) and MIPAS (MIPAS space) observations and with the model (model space) outputs and at three different levels: 121 hPa (upper troposphere), 100 hPa (tropopause) and 68 hPa (lower stratosphere) in January and February 2012. In the MLS space, the analyses behave consistently with the MLS observations from the upper troposphere to the lower stratosphere. In the model space, the analyses are wetter than the reference atmosphere as represented by ARPEGE and MLS in the upper troposphere (121 hPa) and around the tropopause (100 hPa), but are consistent with MLS and MIPAS in the lower stratosphere (68 hPa). In the MIPAS space, the sensitivity and the vertical resolution of the MIPAS data set at 121 and 100 hPa prevent assessment of the behaviour of the analyses at 121 and 100 hPa, particularly over intense convective areas as the South American, the African and the Maritime continents but, in the lower stratosphere (68 hPa), the analyses are very consistent with MIPAS. Sensitivity studies show the improvement on the H2O analyses in the tropical UTLS when assimilating space-borne measurements of better quality, particularly over the convective areas.
HEP computing is approaching the end of an era when simulation parallelization could be performed simply by running one instance of full simulation per core. The increasing number of cores and ...appearance of hardware-thread support both pose a severe limitation on memory and memory-bandwidth available to each execution unit. Typical simulation and reconstruction jobs of AliROOT (offline framework of the ALICE experiment at LHC) do not differ significantly in memory usage - but the input/output rate of reconstruction is approximately three times higher. This makes simulation a more natural candidate for parallelization, especially since the simulation code is relatively stable while the reconstruction code is not expected to settle until the detector is fully calibrated with real data and understood under stable running conditions. We have chosen to use multi-threading solution with one primary particle and all its secondaries being tracked by a given thread. This model corresponds well to Pb-Pb ion collision simulation where 60,000 primary particles need to be transported. After the MC processing of a primary particle is completed, the same thread also performs output serialization. Modifications of ROOT, AliROOT and GEANT3 that were required to perform this task are discussed. Performance of the parallelized version of simulation under varying running conditions is presented.
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