Volcanic activity has frequently been linked to Quaternary environmental change, either by driving climate modification 1,2 or in response to environmental changes 3 . Although a link has been established between large explosive eruptions and small (0.5 ЊC), brief (1-2 years) falls in global temperatures 4 , both the evidence and mechanisms responsible for longer episodes of eruptioninduced planetary cooling remain questionable 1,2,5,6 . In contrast, recent research based on ice-core data suggests that rapid climate changes during the past 110,000 years increased explosive volcanic activity 7 . Here we present a statistical analysis relating the frequency of explosive activity of Mediterranean volcanoes-based on dated 8-11 tephra layers in deep-sea sediment cores-to the rate of late Quaternary sea-level change. The nonlinear correlation between the two is tentatively explained in terms of dynamic responses of the volcanoes to stress-related influences on various spatial scales. The correlation supports a mechanism or mechanisms by which the climate-driven growth and decay of large ice sheets can influence the eruptive chronologies of distant volcanic edifices via changes in global sea level.The possibility that late Quaternary environmental changes influenced the frequency and magnitude of volcanic eruptions has only recently been considered. New research based on the GISP2 ice core 7 has produced a continuous record of explosive volcanism in the Northern Hemisphere over the past 110 kyr. The record identifies distinct periods of enhanced volcanic activity (notably at 35-22 and 17-6 kyr ago) which coincide with periods of rapid environmental change. In areas where active volcanism 3 and Quaternary glaciation coincide, the correlation between the events can be explained by the effect of changing ice volumes on crustal stresses 12 . In contrast, the effect of ice-sheet volume changes on unglaciated volcanic areas remains problematical. Several authors 6,13-15 have proposed that meltwater loading and unloading could influence volcanic activity at sites distant from areas of ice accumulation through the global redistribution of water, although this hypothesis has never been tested. Here we examine the evidence for a link between such a redistribution and explosive volcanic activity, by comparing the temporal distribution of tephra layers in Mediterranean deep-sea cores 8-11 with established global sea-level curves for the late Quaternary period. All the active volcanic centres in this region ( Fig. 1) either form islands or are adjacent to coastlines, excepting Monte Vulture (Italy) which lies ϳ50 km from the sea.The validity of both the correlation, and the proposed model, is crucially dependent on first, the accuracy with which ages are attributed to individual tephra layers, and second, on limited reworking and resedimentation of the tephra. The available data consist of 81 data layers (both megascopic and determined from a high percentage of volcanic glass in the sediment) in deep-sea cores from the Tyrrhenian 10...

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The material properties of ligaments are not well characterized at rates of deformation that occur during high-speed injuries. The aim of this study was to measure the material properties of lateral collateral ligament of the porcine stifle joint in a uniaxial tension model through strain rates in the range from 0.01 to 100/s. Failure strain, tensile modulus and failure stress were calculated. Across the range of strain rates, tensile modulus increased from 288 to 905 MPa and failure stress increased from 39.9 to 77.3 MPa. The strain-rate sensitivity of the material properties decreased as deformation rates increased, and reached a limit at approximately 1/s, beyond which there was no further significant change. In addition, time resolved microfocus small angle X-ray scattering was used to measure the effective fibril modulus (stress/fibril strain) and fibril to tissue strain ratio. The nanoscale data suggest that the contribution of the collagen fibrils towards the observed tissue-level deformation of ligaments diminishes as the loading rate increases. These findings help to predict the patterns of limb injuries that occur at different speeds and improve computational models used to assess and develop mitigation technology.

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This paper summarises the test data obtained from an experimental investigation of reinforced concrete (RC) wide beams, which can also be described as one-way slabs, under low-rate (static) and high-rate (impact) concentrated loading applied at their mid-span. The aim of the work was to investigate key aspects of structural response such as the load–deformation behaviour, crack patterns, strength and failure modes of these basic structural elements under varying levels of loading rate. Three 125 mm thick specimens were studied and they measured 1800 mm long and 360 mm wide. They were simply supported at a span of 1600 mm. One specimen was tested under static loading, and the other two were subjected to impact loading using a drop weight. For both load rates investigated, measurements included strains, deflections and support reactions. Additional measurements for the impact test included accelerations and the use of a high-speed, high-resolution video camera to record the whole test. Digital photography was also used for the low-rate test. The use of digital photography and video recording has proved to be a valuable source of data to validate the readings of the more conventional instrumentation and also to give insight into transient features of the impact test such as crack patterns, particularly those which opened and closed during the test. The comparison between the low-rate and impact behaviour has helped further the understanding of the structural response of RC structures under varying rates of loading.

A levelling network and a horizontal distance measuring network down Mr. Etna's south flank were measured before, during and after the 1983 eruption. We analyse the large movements recorded, using theoretical models of surface displacement, to determine the shape and position of the feeder conduit that supplied magma to the eruption. The results indicate that a dyke, the top surface extending nearly horizontally, connects the eruption site to a point near the Southeast Crater. The top of the dyke lies at an altitude of 2400 m to 2500 r~ and dips between 75 ° and 90 ° to the west.More tentative evidence indicates that the top of the active dyke dropped by about 150 m between the 25th and the 95th day of the eruption, and that a small branching dyke 1 km long was emplaced to the east of the main dyke, but did not attain the surface. The implications of these observation are discussed.

New engineered materials have critical applications in different fields in medicine, engineering and technology but their enhanced mechanical performances are significantly affected by the microstructural design and the sintering process used in their manufacture. This work introduces (i) a methodology for the calculation of the full deflection profile from video recordings of bending tests, (ii) an optimisation algorithm for the characterisation of Young’s modulus, (iii) a quantification of the effects of optical distortions and (iv) a comparison with other standard tests. The results presented in this paper show the capabilities of this procedure to evaluate the Young’s modulus of highly stiff materials with greater accuracy than previously possible with bending tests, by employing all the available information from the video recording of the tests. This methodology extends to this class of materials the possibility to evaluate both the elastic modulus and the tensile strength with a single mechanical test, without the need for other experimental tools.