Traditionally, earthquake impact assessments have been made via fieldwork by non-governmental organisations (NGO's) sponsored data collection; however, this approach is time-consuming, expensive and often limited. Recently, social media (SM) has become a valuable tool for quickly collecting large amounts of first-hand data after a disaster and shows great potential for decision-making. Nevertheless, extracting meaningful information from SM is an ongoing area of research. This paper tests the accuracy of the pre-trained sentiment analysis (SA) model developed by the no-code machine learning platform MonkeyLearn using the text data related to the emergency response and early recovery phase of the three major earthquakes that struck Albania on the 26th November 2019. These events caused 51 deaths, 3000 injuries and extensive damage. We obtained 695 tweets with the hashtags: #Albania #AlbanianEarthquake, and #albanianearthquake from the 26th November 2019 to the 3rd February 2020. We used these data to test the accuracy of the pre-trained SA classification model developed by MonkeyLearn to identify polarity in text data. This test explores the feasibility to automate the classification process to extract meaningful information from text data from SM in real-time in the future. We tested the no-code machine learning platform's performance using a confusion matrix. We obtained an overall accuracy (ACC) of 63% and a misclassification rate of 37%. We conclude that the ACC of the unsupervised classification is sufficient for a preliminary assessment, but further research is needed to determine if the accuracy is improved by customising the training model of the machine learning platform.
Climate Dynamics - We investigate heat waves defined as periods of at least 3 consecutive days of extremely high daily maximum temperature affecting at least 30 % of western Europe. This... 相似文献
The past record of global earth surface temperatures is unable to offer quantitative evidence about the amplitude of climate sensitivity, due to the competing effects of long-lived greenhouse gases and short-lived aerosols. This factor constitutes one of the reasons why uncertainties about climate sensitivity have remained almost unchanged for more than 30 years, and it is also limiting our current capacity to propose reliable climate projections for the coming century. This paper offers a short review of the studies that have dealt with this issue. A number of approaches aim at a process-oriented diagnostic of current models. These studies are in constant progress since the launch of remote-sensing instruments, such as those from the A-train satellite constellation. Past climate fluctuations may also offer some limited possibilities to discriminate the effects of greenhouse gases and aerosols. There is therefore a real hope that climate projections may eventually become more accurate, which would be extremely useful in monitoring global warming during the next decades. 相似文献
A one-dimensional model is used to analyze, at the local scale, the response of the equatorial Atlantic Ocean under different
meteorological conditions. The study was performed at the location of three moored buoys of the Pilot Research Moored Array
in the Tropical Atlantic located at 10° W, 0° N; 10° W, 6° S; and 10° W, 10° S. During the EGEE-3 (Etude de la circulation
océanique et de sa variabilité dans le Golfe de Guinee) campaign of May–June 2006, each buoy was visited for maintenance during
2 days. On board the ship, high-resolution atmospheric parameters were collected, as were profiles of temperature, salinity,
and current. These data are used here to initialize, force, and validate a one-dimensional model in order to study the diurnal
oceanic mixed-layer variability. It is shown that the diurnal variability of the sea surface temperatures is mainly driven
by the solar heat flux. The diurnal response of the near-surface temperatures to daytime heating and nighttime cooling has
an amplitude of a few tenths of degree. The computed diurnal heat budget experiences a net warming tendency of 31 and 27 W m−2 at 0° N and 10° S, respectively, and a cooling tendency of 122 W m−2 at 6° S. Both observed and simulated mixed-layer depths experience a jump between the nighttime convection phase and the
well-stabilized diurnal water column. Its amplitude changes dramatically depending on the meteorological conditions occurring
at the stations and reaches its maximum amplitude (~50 m) at 10° S. At 6° and 10° S, the presence of barrier layers is observed,
a feature that is clearer at 10° S. Simulated turbulent kinetic energy (TKE) dissipation rates, compared to independent microstructure
measurements, show that the model tracks their diurnal evolution reasonably well. It is also shown that the shear and buoyancy
productions and the vertical diffusion of TKE all contribute to the supply of TKE, but the buoyancy production is the main
source of TKE during the period of the simulation. 相似文献
The Raman frequencies of quartz are used to evaluate deviatoric stresses in rocksalt-structure media in diamond-anvil cell experiments to pressures up to 20 GPa. The piezospectroscopic effect in quartz is modeled by first-principles calculations. Non-hydrostatic stresses measured in halogen salts give yield strength estimates of 3 GPa in the B1 structure (NaCl), and 4.5 GPa for the B2 structure (KCl and KBr). Raman measurements in MgO show that the yield strength is reached at around 6 ± 1 GPa. Measurements on quartz alone indicate similar yield strength. The estimated yield strength in MgO is thus likely a lower bound, in consistency with former radial X-ray diffraction measurements that gave a yield strength of 8 ± 1 GPa, and lower-pressure large-volume press experiments indicating a yield strength of 6 GPa at 5 GPa. Former values of the yield strength below 2 GPa determined by pressure gradient measurements were underestimated due to unverified assumptions in boundary conditions. The yield strength increases with increasing coordination of ionic solids, likely contributing to increase viscosity at phase transitions near the upper–lower mantle boundary. 相似文献
Zircon and apatite fission track (FT) thermochronology was applied to investigate the history of cooling and denudation of the Southern Andes between 41° and 42°15′S in relation to the late Cenozoic activity of the Liquiñe-Ofqui fault zone (LOFZ) and the northward migration of the Chile Triple Junction (CTJ). Fifty-six zircon and 51 apatite FT ages, plus 37 apatite confined track-length distributions were obtained mainly from plutonic rocks of the North Patagonian Batholith (NPB) in the main Andean Cordillera. Apatite FT ages and track lengths indicate a stage of rapid cooling at ∼5--3 Ma along both sides of the LOFZ, whereas older Miocene ages with monotonous cooling histories were obtained further away from the fault. Zircon FT ages range from Cretaceous to Pliocene, with marked differences observed along and across the LOFZ. Three different types of temperature-time histories characterise the post-magmatic cooling of the NPB in the region: deep intrusions with moderate and steady cooling rates, intrusions in the upper crust with very slow cooling rates following a stage of initial rapid cooling, and rapidly cooled and exhumed shallow intrusions, the latter with younger ages towards the fault zone. The most prominent denudation episode along the LOFZ is late Miocene to Pliocene, coeval with plate tectonic reconstructions for the arrival and subduction of the Chile Rise beneath the Taitao Peninsula. 相似文献
Karstic aquifers influence flash floods propagation in Mediterranean countries. Near Montpellier, Southern France, discharge
data are recorded on the Coulazou River upstream and downstream of the Aumelas Causse. Two gauging stations are used to describe
the hydrodynamics of this binary karstic system. The first station characterizes the non-karstic catchment area. The second
one is representative of the karstic part of the watershed. Records since April 2004 are used to understand how the river
interacts with a karstic aquifer. Hydrograph analysis of three flash flood events is described. Corresponding discharge time
series recorded at the two gauging stations are used to describe the modification of the hydrographs by auto- and crosscorrelations
analyses. Finally, linear system analyses are used to provide the transfer functions of this binary karstic system according
to the three flood events characteristics (initial conditions, volume, spatial distribution of rainfall, etc.). Theses functions
summarize the hydrodynamic behaviour of the system: their shapes are indicative of the dynamics of the storage, the release
and the contribution to surface waters.
This paper aims at illustrating different case examples of monitoring active coastal evolutions using remote sensing synthetic aperture radar images (ERS 1–2 and Envisat) in humid tropical areas. Effectively, the radar satellite images may be acquired under most climate conditions, especially in cloudy tropical areas. As case examples, we studied herein French Guiana shoreline and its fast evolution under the combined influences of sea currents, sediments and swells. We focused on two aspects of French Guiana littoral evolution: (1) sedimentation and erosion processes linked to mud banks displacements around Kourou City, and (2) around Iracoubo village. Lastly, we compared this short-term sedimentation balance with long-term data showing the discrepancies of short- and long-term littoral evolutions on whole French Guiana. To conclude, this work demonstrates the importance of SAR imagery to provide high-quality and high-frequency update geographic information for coastal management and littoral hazards especially in such tropical humid and cloudy areas. To cite this article: H. Trebossen et al., C. R. Geoscience 337 (2005).相似文献