Subsidence and thermal history of an inverted Late Jurassic‐Early Cretaceous extensional basin (Cameros,North‐central Spain) affected by very low‐ to low‐grade metamorphism

The Cameros Basin (North Spain) is a Late Jurassic‐Early Cretaceous extensional basin, which was inverted during the Cenozoic. It underwent a remarkable thermal evolution, as indicated by the record of anomalous high temperatures in its deposits. In this study, the subsidence and thermal history of the basin is reconstructed, using subsidence analysis and 2D thermal modelling. Tectonic subsidence curves provide evidence of the occurrence of two rapid subsidence phases during the syn‐extensional stage. In the first phase (Tithonian‐Early Berriasian), the largest accommodation space was formed in the central sector of the basin, whereas in the second (Early Barremian‐Early Albian), it was formed in the northern sector. These rapid subsidence phases could correspond to relevant tectonic events affecting the Iberian Plate at that time. By distinguishing between the initial and thermal subsidence and defining their relative magnitudes, Royden's (1986) method was used to estimate the heat flow at the end of the extensional stage. A maximum heat flow of 60–65 mW/m² is estimated, implying only a minor thermal disturbance associated with extension. In contrast with these data, very high vitrinite reflectance, anomalously distributed in some case with respect to the typical depth‐vitrinite reflectance relation, was measured in the central‐northern sector of the basin. Burial and thermal data are used to construct a 2D thermal basin model, to elucidate the role of the processes involved in sediment heating. Calibration of the thermal model with the vitrinite reflectance (%Ro) and fluid inclusion (FI) data indicates that in the central and northern sectors of the basin, an extra heat source, other than a typical rift, is required to explain the observed thermal anomalies. The distribution of the %Ro and FI values in these sectors suggests that the high temperatures and their distribution are related to the circulation of hot fluids. Hot fluids were attributed to the hydrothermal metamorphic events affecting the area during the early post‐extensional and inversion stages of the basin.     

Tuning the second-generation SDI: theoretical aspects and real use cases

Spatial data infrastructure (SDI) actors have great expectations for the second-generation SDI currently under development. However, SDIs have many implementation problems at different levels that are delaying the development of the SDI framework. The aims of this article are to identify these difficulties, in the literature and based on our own experience, in order to determine how mature and useful the current SDI phenomena are. We can then determine whether a general reconceptualization is necessary or rather a set of technical improvements and good practices needs to be developed before the second-generation SDI is completed. This study is based on the following aspects: metadata about data and services, data models, data download, data and processing services, data portrayal and symbolization, and mass market aspects. This work aims to find an equilibrium between user-focused geoportals and web service interconnection (the user side vs. the server side). These deep reflections are motivated by a use case in the healthcare area in which we employed the Catalan regional SDI. The use case shows that even one of the best regional SDI implementations can fail to provide the required information and processes even when the required data exist. Several previous studies recognize the value of applying Web 2.0 and user participation approaches but few of these studies provide a real implementation. Another objective of this work is to show that it is easy to complement the classical, international standard-based SDI with a participative Web 2.0 approach. To do so, we present a mash-up portal built on top of the Catalan SDI catalogues.     

Application of LPW and SAI SAFNWC/MSG satellite products in pre-convective environments

The Spinning Enhanced Visible and Infrared Imagery (SEVIRI) instrument, on board the Meteosat Second Generation (MSG), is a radiometer with eight infrared (IR) spectral bands. Seven of these channels are used to retrieve Layer Precipitable Water (LPW) and Stability Analysis Imagery (SAI). Both products are the PGE07 and the PGE08 of SAFNWC (Satellite Application Facility on support to Nowcasting and Very Short-Range Forecasting). The authors at Instituto Nacional de Meteorología (INM) have developed the LPW and SAI algorithms, in the SAFNWC framework. Both products are retrieved using statistical retrieval based on neural networks. The main advantage of these algorithms versus physical retrieval algorithms is the independence from the Numerical Weather Prediction (NWP) models. The LPW provides information on the water vapor contained in a vertical column of unit cross-section area in three layers in the troposphere (low, middle and high) and in the total layer in cloud free areas. The SAI provides estimations of the atmospheric instability in cloud free areas, in particular the Lifted Index (LI).The stability and precipitable water obtained with both products are routinely generated every 15 min at a satellite horizontal resolution of 3 km in NADIR. A significant advantage of these MSG products, compared to traditional measurements such as radiosondes, is their ability to measure high resolution temporal and spatial variations of atmospheric stability and moisture in pre-convective environments. The main disadvantage is that they do not have the vertical resolution of radiosonde. The MSG moisture and stability time trend fields are especially useful during the period preceding the outbreak of convection due to the high resolution. Once the outbreak of convection occurs, the products calculated in the clear air pixels surrounding the convective system will allow to foresee the evolution of the convection.     

Interest in intermediate soft-classified maps in land change model validation: suitability versus transition potential

This study compares two types of intermediate soft-classified maps. The first type uses land use/cover suitability maps based on a multi-criteria evaluation (MCE). The second type focuses on the transition potential between land use/cover categories based on a multi-layer perceptron (MLP). The concepts and methodological approaches are illustrated in a comparable manner using a Corine data set from the Murcia region (2300 km², Spain) in combination with maps of drivers that were created with two stochastic, discretely operating, commonly used tools (MCE in CA_MARKOV and MLP in Land Change Modeler). The importance of the different approaches and techniques for the obtained results is illustrated by comparing the specific characteristics of both approaches by validating the suitability versus transition potential maps to each other using a Spearman correlation matrix and, between the Corine maps, using classical ROC (receiver operating characteristic) statistics. Then, we propose a new use of ROC statistics to compare these intermediate soft-classified maps with their respective hard-classified maps of the models for each category. The validation of these results can be beneficial in choosing a suitable model and provide a better understanding of the implications of the different modeling steps and the advantages and limitations of the modeling tools.     

THERMAP: a mid-infrared spectro-imager for space missions to small bodies in the inner solar system

We present THERMAP, a mid-infrared spectro-imager for space missions to small bodies in the inner solar system, developed in the framework of the MarcoPolo-R asteroid sample return mission. THERMAP is very well suited to characterize the surface thermal environment of a NEO and to map its surface composition. The instrument has two channels, one for imaging and one for spectroscopy: it is both a thermal camera with full 2D imaging capabilities and a slit spectrometer. THERMAP takes advantage of the recent technological developments of uncooled microbolometer arrays, sensitive in the mid-infrared spectral range. THERMAP can acquire thermal images (8–18 μm) of the surface and perform absolute temperature measurements with a precision better than 3.5 K above 200 K. THERMAP can acquire mid-infrared spectra (8–16 μm) of the surface with a spectral resolution Δλ of 0.3 μm. For surface temperatures above 350 K, spectra have a signal-to-noise ratio >60 in the spectral range 9–13 μm where most emission features occur.     

Evidence of high‐energy events in shelly layers interbedded in coastal Holocene sands in Cadiz Bay (south‐west Spain)

In some present‐day coastal areas, recent inactive deposits now outside the reach of sea agents can be observed. These deposits, although formed under different climatic and sea level conditions, often show similar facies to current littoral deposits. They are frequently interpreted as old dunes and beach ridges, or as abandoned spit bars, representative of previous dynamic stages. Nevertheless, in coastal areas which have been subjected to highly‐energetic events similar deposits can also be found. When a dynamic event acts on several adjacent environments, the transported and re‐deposited sediments can create homogeneous deposits with similar facies, that are easily confused. In this work, shelly layers interbedded in relict littoral sands located in the La Algaida pinewood, on the edge of the Rio San Pedro tidal channel, in Cadiz Bay (south‐west Spain) have been studied. The main constituents of the shelly beds are Glycimeris valves, organisms which are no longer found as live specimens in the present‐day sea bed of Cadiz Bay. From their appearance, the origin of these shelly beds could be related to sea washovers generated by tidal or storm action, but their disposition and height over the present sea level implies that even higher energy agents were involved in their formation, such as major storms or tsunami waves. The most significant process was the mobilization of the sub‐tidal and littoral sediments and their dispersal and re‐sedimentation, both lengthways and widthways of the coast, giving way to homogeneous sandy deposits in all littoral environments some of which are now outside the reach of current sea agents. The exception is the present‐day shore of the San Pedro tidal channel, where the sediments are being reworked by tidal and small wave action. If the proximity of the study zone to the limit of the African and Iberian plates is considered, where several historical earthquakes and tsunamis have taken place, it is possible to think that these deposits could be a consequence of sporadic and successive washovers, generated by tsunamis occurring between ad 800 and ad 1200. Sedimentological and historical data indicate an increase in seismic and tsunami activity during this period of time, while the shelly layers would be the consequence of the most intense pulses occurring during these high‐energy events. Copyright © 2009 John Wiley & Sons, Ltd.     

Lessons Learned from the 2011 Great East Japan Tsunami: Performance of Tsunami Countermeasures, Coastal Buildings, and Tsunami Evacuation in Japan

In 2011, Japan was hit by a tsunami that was generated by the greatest earthquake in its history. The first tsunami warning was announced 3 min after the earthquake, as is normal, but failed to estimate the actual tsunami height. Most of the structural countermeasures were not designed for the huge tsunami that was generated by the magnitude M = 9.0 earthquake; as a result, many were destroyed and did not stop the tsunami. These structures included breakwaters, seawalls, water gates, and control forests. In this paper we discuss the performance of these countermeasures, and the mechanisms by which they were damaged; we also discuss damage to residential houses, commercial and public buildings, and evacuation buildings. Some topics regarding tsunami awareness and mitigation are discussed. The failures of structural defenses are a reminder that structural (hard) measures alone were not sufficient to protect people and buildings from a major disaster such as this. These defenses might be able to reduce the impact but should be designed so that they can survive even if the tsunami flows over them. Coastal residents should also understand the function and limit of the hard measures. For this purpose, non-structural (soft) measures, for example experience and awareness, are very important for promoting rapid evacuation in the event of a tsunami. An adequate communication system for tsunami warning messages and more evacuation shelters with evacuation routes in good condition might support a safe evacuation process. The combination of both hard and soft measures is very important for reducing the loss caused by a major tsunami. This tsunami has taught us that natural disasters can occur repeatedly and that their scale is sometimes larger than expected.     

Trends of tropical deforestation in Southeast Mexico

We assessed deforestation in Southeast Mexico (a surface area of 29 000 km² in seven states) through the comparison of land use/land cover maps at a scale of 1:250 000. This facilitated mapping of the land use/land cover change (LULCC) processes and calculation of the rates of change and the change matrix for the period 1978–2000. An original method was used to assess the accuracy of the LULCC map. The verification sites were selected through a stratified random sampling and were corroborated with aerial photographs for 1978 and 2000. Error matrices were elaborated using both hard and fuzzy set approaches in order to take into account the errors related to generalization of the map in fragmented landscapes. The results showed an average annual deforestation rate of 1.1 per cent which represents an average annual loss of 190 000 ha of forest, or an estimated total reduction of 4.2 million ha over 22 years. Furthermore, deforestation processes are concentrated in some areas such as Yucatan and Chiapas states, which registered major forest conversions to grassland and slash‐burning. The overall accuracy of the LULCC map, assessed with hard and fuzzy set approaches, was 72 per cent and 88 per cent respectively.     

Mapping land cover changes in Mexico, 1976–2000 and applications for guiding environmental management policy

Land use conversion typically implicates deforestation and fragmentation of primary land cover types, which invariably translates into impoverishment of both natural and cultural capital. Understanding where conversion is taking place crucially underpins sound environmental policy instruments to prevent these enormous social and economic costs. This paper examines 30 years of semi‐detailed (1:250 000) land cover mapping in Mexico. Pre‐existing analogue databases describing land cover patterns in the 1970s and 1990s were reviewed, corrected, reorganized and transformed into a digital format. Current land cover patterns were depicted by conducting updated reinterpretation on Landsat ETM+ imagery. Digital cartographic overlaying was performed and the results were used to construct a spatially explicit land use/land cover change (LULCC) database with an additional accuracy assessment procedure. The value of the results of this analysis is also seen in the light of their direct applications for identifying critical watershed trends, for guiding the allocation of financial funds for sound land use planning and for assessing the effectiveness of established protected areas. This effort highlights the importance of new and more effective geographical approaches to depict, understand and contribute to informed measures to mitigate ongoing negative trends in land cover and climatic changes.