Additive effects of climate change and human hunting explain population decline and extinction in cave bears

Cave bears (Ursus spelaeus) are an iconic component of the European late Quaternary Ice Age megafauna. Recent demographic analyses based on cave bear mtDNA sequences and refined radiocarbon dating indicate that cave bear population size and genetic diversity started to decline some 50 kilo years ago (kya). Hence, neither the coldest phase of the last glaciation (started some 24 kya), nor the colonization of Europe by Palaeolithic hunters (started some 45 kya) coincides with the beginning of population decline. Here, we reconstructed cave bear climatic niche evolution through time. Then, we performed spatially explicit population viability analyses to assess cave bear demographics through time in response to climatic changes, human effects on bear survival and their combination. We found that climate change was responsible for a 10‐fold decrease in cave bear population size after 40 kya. However, climate change on its own could not explain U. spelaeus extinction at 24 kya. Additional negative effects consistent with human population expansion are required to explain both U. spelaeus' retreat from eastern Europe since 40 kya and its final extinction.     

Establishing a threshold for rainfall-induced landslides by a kinetic energy–duration relationship

Many investigators have attempted to define the threshold of landslide failure, that is, the level of the selected climatic variable above which a rainfall-induced landslide occurs. Intensity–duration (I–d) relationships are the most common type of empirical thresholds proposed in the literature for predicting landslide occurrence induced by rainfall. Recent studies propose the use of the kinetic power per unit volume of rainfall (J m⁻² mm⁻¹) to quantify the threshold of landslides induced by rainfall. In this paper, the relationship between rainfall duration and kinetic power corresponding to landslides triggered by rain was used to propose a new approach to define the threshold for predicting landslide occurrence. In particular, for the first time, a kinetic power per unit volume of rainfall–duration relationship is proposed for defining the minimum threshold needed for landslide failure. This new method can be applied using commonly used relationship for estimating the kinetic power per unit volume of rainfall and a new equation based on the measured raindrop size distribution. The applicability of this last method was tested using the data of rainfall intensity, duration and median volume diameter for 51 landslides in Taiwan. For the 51 landslides, the comparison between the measured pairs' kinetic power–duration and all selected relationships demonstrated that the equation based on the measured raindrop size distribution is the best method to define the landslide occurrence threshold, as it is both a process-oriented approach and is characterized by the best statistical performance. This last method has also the advantage to allow the forecasting of landslide hazard before the end of the rainfall event, since the rainfall kinetic power threshold value can be exceeded for a time interval less than the event duration.     

Large dyke intrusion and small eruption: The December 24, 2018 Mt. Etna eruption imaged by Sentinel‐1 data

On December 24th, Mt. Etna volcano underwent a seismic crisis beneath the summit and upper southern flank of the volcano, accompanied by significant ash emission. Eruptive fissures opened at the base of summit craters, propagating SE‐wards. This lateral eruption lasted until December 27th. Despite the small eruption, seismic swarm and ground deformation were very strong. Sentinel‐1 interferograms show a wide and intense ground deformation with some additional features related to volcano‐tectonic structures. We inverted DInSAR data to characterise the magma intrusion. The resulting model indicates that a large dyke intruded but aborted its upraise at about the sea level; however, this big intrusion stretched the edifice, promoting the opening of the eruptive fissures fed by a shallower small dyke, and activating also several faults. This model highlights that a big intrusion beneath a structurally complex volcano represents a main issue even if the eruption is aborted.     

Improving radiometry of imaging spectrometers by using programmable spectral regions of interest

Programmable imaging spectrometers can be adjusted to fit specific application requirements that differ from the instrument initial spectral design goals. Sensor spectral characteristics and its signal-to-noise ratio (SNR) can be changed by applying customized online binning patterns.We present a software utility that generates application driven spectral binning patterns by using an SNR dependent sensor model. The utility, named BinGO (BInning patterN Generator and Optimiser), is used to produce predefined binning patterns that either (a) allow an existing imaging spectrometer to optimize its spectral characteristics for a specific application, (b) allow an existing imaging spectrometer to spectral and/or spatially emulate another instrument, or (c) design new multispectral or imaging spectrometer missions (i.e. spaceborne, airborne, terrestrial). We present a variety of BinGO case studies, including the simulation of airborne (APEX) [Itten, K.I. et al., 2008. APEX — The hyperspectral ESA Airborne Prism Experiment. Sensors 8(1), 1–25], spaceborne (SENTINEL III) [Nieke, J., Frerick, J., Stroede, J., Mavrocordatos, C., Berruti, B., 2008. Status of the optical payload and processor development of ESA’s Sentinel 3 mission. In: Proceedings of the Geoscience and Remote Sensing Symposium IGARSS 2008, pp. 427–430], as well as scientific and performance optimized approaches. We conclude that the presented approach can successfully be used to increase the efficiency of spectral information retrieval by using imaging spectroscopy data and to simulate various missions and requirements, finally supporting proper trade-off decisions to be made between performance optimization and scientific requirements. In addition, if specific sensor parameters are known, BinGO can also model other imaging spectrometers.     

Tuned vibration absorbers with dry friction damping

The response of a linear SDOF system subjected to harmonic excitation to which a Tuned Vibration Absorber with linear stiffness and dry friction damping is attached is considered. Based on an intuitive examination of the physical behaviour of the system, closed-form expressions for TMD optimum parameters and for the steady-state amplitudes of vibration are presented. Two examples allow the comparison between the predicted behaviour and that found by numerically integrating the equations of motion. Copyright © 1999 John Wiley & Sons, Ltd.     

Contribution to knowledge regarding the sources of earthquakes on the island of Ischia (Southern Italy)

Natural Hazards - This paper analyses data regarding the seismicity and ground deformations of the island of Ischia. The goal is to describe these phenomena as a space–time process, exploring...     

From flood risk mapping toward reducing vulnerability: the case of Addis Ababa

Natural Hazards - Flood risk maps for the built environment can be obtained by integrating geo-spatial information on hazard, vulnerability and exposure. They provide precious support for strategic...     

The upper Miocene diatomaceous sediments of the northernmost Mediterranean region: A lamina-scale investigation of an overlooked palaeoceanographic archive

During the late Miocene the Mediterranean experienced a dramatic intensification of opaline accumulation, recorded by the deposition of diatomaceous sediments. The fine lamination of these deposits potentially records annual to sub-annual palaeoceanographic processes that occurred during a critical phase of the geodynamic evolution of the Mediterranean basin, which eventually led to the Messinian salinity crisis. The diatomaceous facies has been interpreted by previous researchers as the product of intensified upwelling currents and of bottom anoxia formation in the Mediterranean basin. However, until now, no efforts have been made to unravel the sedimentological and micropalaeontological content of these deposits at the lamina-scale. This paper presents the first case study of a systematic scanning electron microscope-based morphological investigation of the diatomaceous sediments deposited during the late Miocene at the northernmost offshoot of the Mediterranean basin (Piedmont Basin, north-west Italy). Using a non-invasive analytical approach, six faciological components (laminae, laminated packets, non-laminated intervals, burrows, opal-rich aggregates and mixed pelletal structures) and their relationships are described and interpreted herein. Following the lamina-scale study of these sediments, an annual sedimentary cycle could be identified and an accumulation rate (ca 50 cm kyr⁻¹) inferred that is atypical for a setting actively influenced by upwelling. The role played by the entanglement of diatom valves in creating a physical barrier to the bioturbation is here emphasized as the main process responsible for the preservation of the laminated fabric of diatomaceous sediments, challenging the supposed role of deep anoxia. These results suggest that the late Miocene diatomaceous deposition in the Piedmont Basin cannot be univocally considered as a by-product of upwelling intensification and seafloor oxygen depletion.     

Anti-erosive effectiveness of Eucalyptus coppices through the cover management factor estimate

In this paper sediment yield data, measured from 1978 to 1994 in two small Calabrian basins (W2 and W3) reafforested with eucalyptus trees (Eucalyptus occidentalis Engl.), and the Modified Universal Soil Loss Equation (MUSLE) applied in a distributed form are used to evaluate the anti-erosive effects of eucalyptus cover. At first step the sediment yield measurements observed in W2 basin are used to estimate a single cover management factor representative of the eucalyptus coppice and equal to the median value (0·164) of the cover management factor values calculated for each runoff event. Then, the reliability of the selected representative cover management factor is verified on W3 by comparing the cumulative distribution function (CDF) of the measured sediment yield with the CDF of the calculated one. Finally, the temporal analysis of the crop and management factor is developed searching, at monthly and annual scale, the correlation between crop anti-erosive effectiveness and rainfall erosivity index. © 1998 John Wiley & Sons, Ltd.