Rapid finite-fault analysis of large Mexico earthquakes using teleseismic P waves     

Mendoza  C.  Martínez-López  M. R. 《Journal of Seismology》2022,26(2):333-342

Journal of Seismology - We propose a rapid, finite-fault inversion procedure to derive first-order estimates of the coseismic slip following large Mw > 7 earthquakes in Mexico using...  相似文献   

Hydrodynamics associated to the X-ray light curve of A0620-00     

Y. Coronado  S. Mendoza 《Astrophysics and Space Science》2015,357(2):1-5

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Influences of local weather, large-scale climatic drivers, and the ca. 11 year solar cycle on lake ice breakup dates; 1905–2004     

Sapna Sharma  John J. Magnuson  Gricelda Mendoza  Stephen R. Carpenter 《Climatic change》2013,118(3-4):857-870

We investigate the temporal patterns in inter-annual variability in ice breakup dates for Lakes Mendota and Monona, Wisconsin, between 1905 and 2004. We analyze the contributions of long-term trends attributed to climate change, local weather, indices of sunspots, and large-scale climatic drivers, such as the North Atlantic Oscillation (NAO) and El Niňo Southern Ocean Index (ENSO) on time series of lake-ice breakup. The relative importance of the aforementioned explanatory variables was assessed using linear regression and variation partitioning models accounting for cyclic temporal dynamics as represented by Moran Eigenvector Maps (MEM). Model results explain an average of 58 % of the variation in ice breakup dates. A combination of the long-term linear trends, rain and snowfall in the month prior to breakup, air temperature in the winter prior to breakup, cyclic dynamics associated with sunspot numbers, ENSO, and for Lake Mendota, NAO, all significantly influence the timing of ice breakup. Significant cycle lengths were 3.5, 9, 11, and 50 years. Despite their proximity, Lakes Mendota and Monona exhibit differences in how and which explanatory variables were incorporated into the models. Our results indicate that lake ice dynamics are complex in both lakes and multiple interacting processes explain the residuals around the linear warming trends that characterize lake ice records.  相似文献   

Modelling the effect of an assumed cosmic ray-modulated global cloud cover on the terrestrial surface temperature     

J. Ramírez  B. Mendoza  V. Mendoza  J. Adem 《Journal of Atmospheric and Solar》2004,66(18):263

We have used the thermodynamic model of the climate to estimate the effect of variations in the oceanic cloud cover on the surface temperature of the Earth in the North Hemisphere (NH) during the period 1984–1990. We assume that the variations in the cloud cover are proportional to the variation of the cosmic ray flux measured during the same period. The results indicate that the effect in the temperature is slightly noticeable when we consider the surface hemispheric temperature on July 1987, finding an average temperature anomaly between −0.06°C and −0.14°C, along a latitudinal band between 20° and 40°. The surface temperature averaged globally in the NH presents a decrease of 0.01°C in average, which is almost the same for continents and oceans. However, these values are not significant when compared to the overall variability of the time series with and without forcing.  相似文献   

Analytic solutions to the accretion of a rotating finite cloud towards a central object – I. Newtonian approach     

S. Mendoza  E. Tejeda  E. Nagel † 《Monthly notices of the Royal Astronomical Society》2009,393(2):579-586

We construct a steady analytic accretion flow model for a finite rotating gas cloud that accretes material to a central gravitational object. The pressure gradients of the flow are considered to be negligible, and so the flow is ballistic. We also assume a steady flow and consider the particles at the boundary of the spherical cloud to be rotating as a rigid body, with a fixed amount of inwards radial velocity. This represents a generalization to the traditional infinite gas cloud model described by Ulrich. We show that the streamlines and density profiles obtained deviate largely from the ones calculated by Ulrich. The extra freedom in the choice of the parameters on the model can naturally account for the study of protostars formed in dense clusters by triggered mechanisms, where a wide variety of external physical mechanisms determine the boundary conditions. Also, as expected, the model predicts the formation of an equatorial accretion disc about the central object with a radius different from the one calculated by Ulrich.  相似文献   

Safety factor nomograms for homogeneous earth dams less than ten meters high     

F.J. Colomer Mendoza  A. Ferrer Gisbert  A. Gallardo Izquierdo  M.D. Bovea 《Engineering Geology》2009,105(3-4):231-238

Homogeneous earth dams that are waterproofed with geomembranes are a suitable option for storing water and other sorts of liquids, like leachates from landfills. Such dams do not require complicated engineering technical calculations, their cost is usually low and they are not difficult to construct. To ensure the geotechnical safety of the dam, the slopes of the embankment must be correctly designed and constructed. This paper provides a set of nomograms which allow the user to get the safety factor of the slopes immediately. In some cases, it is only necessary to know previously the material classification according to the Unified Soil Classifications System. From this information it can be determined whether the material is appropriate or not. If the material classification is not available, geotechnical data of the material used in the construction of the embankment are needed. Examples of the application of nomograms are presented. Secondly, the paper includes a set of equations to calculate quickly the safety factor of a slope of earth upper than 7.5 m height.  相似文献   

On Mid-Term Periodicities in Sunspot Groups and Flare Index     

Blanca Mendoza  V��ctor Manuel Velasco-Herrera 《Solar physics》2011,271(1-2):169-182

In this work we study the mid-term periodicities (MTPs), between 1 and 2 years, of the sunspot groups and the flare index (FI), by separating the data into hemispheres and spectral bands (SBs) according to the most significant periodicities presented by these phenomena. We found that the MTP of sunspot groups has a diminished power during the Modern Minimum and an increased power during the Modern Maximum, with the exception of cycle 20. For flares, the MTP has a diminished power during the low activity cycle 20, and an increased power during cycles 21 and 22. Therefore, for both sunspot groups and FI, cycle 20 shows a very diminished power followed by the active and higher-power cycles 21 and 22; cycle 23 shows a weaker power than cycles 21 and 22. It is uncertain whether MTP can be a precursor of a long-term minimum of solar activity or not, as has been previously suggested. Also, there is no one-to-one correlation between the cycle intensity and the importance of MTP. Concerning the quasi-biennial periodicities and the theory of two kinds of dynamos, we notice the tendency that higher-power cycles mean weaker coupling in the model. Concerning the hemispheric north-south asymmetry, for sunspot groups the southern hemisphere dominates in most of the SBs, while for FI the northern hemisphere dominates for all the SBs. Additionally, the time lag found between the two hemispheres indicates that the degrees of coupling in the photosphere for sunspot groups and in the corona for flares are between moderate and strong. Finally, the modulation shown by the MTP time series suggests that these periodicities are the product of chaotic quasi-periodic processes and not of stochastic processes.  相似文献   

Probabilistic data integration for characterization of spatial distribution of residual LNAPL     

Amir H. Hosseini  Clayton V. Deutsch  Kevin W. Biggar  Carl A. Mendoza 《Stochastic Environmental Research and Risk Assessment (SERRA)》2010,24(5):735-749

The spatial distribution of residual light non-aqueous phase liquid (LNAPL) is an important factor in reactive solute transport modeling studies. There is great uncertainty associated with both the areal limits of LNAPL source zones and smaller scale variability within the areal limits. A statistical approach is proposed to construct a probabilistic model for the spatial distribution of residual NAPL and it is applied to a site characterized by ultra-violet-induced-cone-penetration testing (CPT–UVIF). The uncertainty in areal limits is explicitly addressed by a novel distance function (DF) approach. In modeling the small-scale variability within the areal limits, the CPT–UVIF data are used as primary source of information, while soil texture and distance to water table are treated as secondary data. Two widely used geostatistical techniques are applied for the data integration, namely sequential indicator simulation with locally varying means (SIS–LVM) and Bayesian updating (BU). A close match between the calibrated uncertainty band (UB) and the target probabilities shows the performance of the proposed DF technique in characterization of uncertainty in the areal limits. A cross-validation study also shows that the integration of the secondary data sources substantially improves the prediction of contaminated and uncontaminated locations and that the SIS–LVM algorithm gives a more accurate prediction of residual NAPL contamination. The proposed DF approach is useful in modeling the areal limits of the non-stationary continuous or categorical random variables, and in providing a prior probability map for source zone sizes to be used in Monte Carlo simulations of contaminant transport or Monte Carlo type inverse modeling studies.  相似文献   

The impact of gravel extraction on groundwater dependent wetlands and lakes in the Boreal Plains, Canada   总被引：1，自引：1，他引：0  

B. D. Smerdon  C. A. Mendoza  K. J. Devito 《Environmental Earth Sciences》2012,67(5):1249-1259

The impact of gravel excavation on a groundwater dependent ecosystem (GDE) in a glacial outwash plain was determined using a combination of time-series stable isotopic measurements (??²H and ??¹⁸O) and a numerical flow model of lake?Cgroundwater interaction. Isotopic analyses of the lake and groundwater indicated a shift from a dominance of evaporative enrichment to more meteoric conditions, confirming the hypothesis of increased recharge following forest clearing and gravel extraction from an esker on the outwash plain. The effect of these land-use changes on source water for the GDE was quantified by simulating the lake water budget, seepage, and groundwater conditions for a period spanning pre- and post-mining activity. Enhanced cycling of shallow groundwater, driven by increased recharge in the gravel excavation area, was predicted to cause annual groundwater discharge pulses greater than baseline conditions for the groundwater-fed lake. The additional groundwater discharge represents approximately 4% of the annual lake budget, increasing the flushing rate of the lake. The influence of regional groundwater conditions, represented by variation of water table gradient and outwash hydraulic conductivity, and an alternative excavation location were investigated in a sensitivity analysis. Simulation results illustrate that a simple groundwater capture zone analysis for the GDE could be used to determine a location for gravel excavation that would reduce impact on GDE water source.  相似文献   

Location of Moderate-Sized Earthquakes Recorded by the NARS�CBaja Array in the Gulf of California Region Between 2002 and 2006     

Raul R. Castro  Arturo Perez-Vertti  Ignacio Mendez  Antonio Mendoza  Luis Inzunza 《Pure and Applied Geophysics》2011,168(8-9):1279-1292

We relocated the hypocentral coordinates of small to moderate-sized earthquakes reported by the National Earthquake Information Center (NEIC) between April 2002 and August 2006 in the Gulf of California region and recorded by the broadband stations of the network of autonomously recording seismographs (NARS?CBaja array). The NARS?CBaja array consists of 19 stations installed in the Baja California peninsula, Sonora and Sinaloa, Mexico. The events reported by the preliminary determinations of epicenters (PDE) catalog within the period of interest have moment magnitudes (M _w) ranging between 1.1 and 6.7. We estimated the hypocentral location of these events using P and S wave arrivals recorded by the regional broadband stations of the NARS?CBaja and the RESBAN (Red Sismológica de Banda Ancha) arrays and using a standard location procedure with the HYPOCENTER code (Lienert and Havskov in Seism Res Lett 66:26?C36, 1995) as a preliminary step. To refine the location of the initial hypocenters, we used the shrinking box source-specific station term method of Lin and Shearer (J Geophys Res 110, B04304, 2005). We found that most of the seismicity is distributed in the NW?CSE direction along the axis of the Gulf of California, following a linear trend that, from north to south, steps southward near the main basins (Wagner, Delfin, Guaymas, Carmen, Farallon, Pescadero and Alarcon) and spreading centers. We compared the epicentral locations reported in the PDE with the locations obtained using regional arrival times, and we found that earthquakes with magnitudes in the range 3.2?C5.0?mb differ on the average by as much as 43?km. For the M _w magnitude range between 5 and 6.7 the discrepancy is less, differing on the average by about 25?km. We found that the relocated epicenters correlate well with the main bathymetric features of the Gulf.  相似文献