Instrumental seismological data since 1900 for northeastern Italy

Statistical analyses on a catalogue of instrumental data for earthquakes in northeastern Italy since 1900 are presented. The different types of magnitude, which are the main parameters under study, have been evaluated so as to be as homogeneous as possible. Comparisons of the different magnitude values show linear dependence, at least in the medium magnitude range represented by the available data set. Correlations between the magnitude most significant for this region and chosen macroseismic data indicate a methodology for assessing the macroseismic magnitude of historical earthquakes which seems to be stable.     

Biomass composition and methods for the determination of metabolic reserve polymers in phototrophic sulfur bacteria

To study nutrient fluxes within aquatic ecosystems, the synthesis of biomass and of various storage polymers has been analysed in samples from a meromictic alpine lake. Methods are described for the quantitative determination of whole cell biomass, glycogen, polyhydroxyalkanoates (PHA) and sulfur. Methods were adapted to conditions present in natural environments and tested with samples from blooms of Chromatiaceae and with corresponding laboratory cultures. Dried bacterioplankton-biomass has been analyzed for sulfur, glycogen and polyhydroxyalkanoates, and after complete oxidation for SO ₄ ^2- , NO ₃ ^- and HPO ₄ ^2- . The average elemental composition of biomass from phototrophic sulfur bacteria, depleted of sulfur and carbon storage compounds, was C₃₈₀H₅₈₀O₁₅₃N₆₇P₃S_2.5M, where M stands for the content of the remaining minor elements. C, H, O, N, P and S accounted for 86.7% of the total dry mass. Storage sulfur in natural populations was equivalent to 2.5% to 13.5% of the dry mass; its content varied by 80% within a diurnal cycle. Glycogen contents fluctuated by approximately 50%; they accounted for 7.5% to 15.2% of the dry cell mass. The total content of reserve materials per cell never exceeded 30% of the dry mass. PHA had not been found in appreciable amounts in cells harvested from the natural lake habitat. Under certain conditions in the laboratoryChromatium okenii could be induced, however, to produce polyhydroxyalkanoates. Sulfur, glycogen and PHA contents of 33, 26 and 11%, respectively, were achieved under laboratory-culture conditions. Cells with up to 60% of their dry mass consisting of reserve materials can be obtained under selected laboratory conditions.     

First estimates of the principal directions of strains compared to those of stresses in seismic friuli,NE Italy

Three Cambridge wire strainmeters and a pair of horizontal-pendulum tiltmeters operate since 1978, in a cave in the northern Friuli seismic area. Straightforward considerations, based on the principles of continuum mechanics, permit a first estimate of the secular and seasonal variations of the cave strain rate tensor, under the assumption of homogeneous, constant-volume strain, together with an analysis of the effects on the tensor components of particular tiltmeter installation sites with respect to the orientation of both the strainmeters plane and the principal axes.The area lies at the complex intersection of NW-SE Dinaric rock structures and E-W Alpine ones. The latest period of strong seismic activity there started in mid-1976. The fault-plane solutions of the main shock revealed a direction of maximum compression perpendicular to the Alpine trend, but later in 1976 and 1977 such a direction seemed to have changed, having become perpendicular to the Dinaric trend.A plain analysis of the strain gauge data show that, from 1978 to 1981, the maximum shortening secular strain changed progressively from a SW bearing to a SSE one or even SE one. Hence, it would appear that by 1981 the direction of maximum compression had become Alpine again.In the same time interval, the principal axes of the five observed yearly seasonal strain rates maintained a Dinaric orientation similar to that of the geological structures around the cave.Finally the orientations of the secular strain acceleration principal axes appear to be nearly coaxial with those of the stress obtained from various 1977 fault-plane solutions, the compressional stress corresponding to extensional accelerations andvice-versa. Such observation suggests that the modifications of secular strain rates are related to the stress release connected with the seismic activity.     

A study of the performance of a land surface process model (LSPM)

In this paper, a reliable Land-Surface Process Model (LSPM), which is a new version of the LPM of Ji and Hu (1989), is described. The LSPM has been validated with experimental data measured at two stations in the Po Valley (Northern Italy).     

Volcaniclastic resedimentation on the northern slope of Vesuvius as a direct response to eruptive activity

A new archaeological excavation on the northern slope of Vesuvius has provided invaluable information on the eruptive activity and post-eruptive resedimentation events between the late Roman Empire and 1631. A huge Roman villa, thought to belong to the Emperor Augustus, survived the effects of the 79 a.d. Plinian eruption, but was mainly engulfed in volcaniclastic materials eroded and redeposited immediately after a subsequent eruption or during repose periods. Primary pyroclastic deposits of the 472 a.d. eruption are only few centimeters thick but are overlain by reworked volcaniclastic deposits up to 5 m thick. The resedimented volcaniclastic succession shows distinct sedimentary facies that are interpreted as debris flow deposits, hyperconcentrated flow deposits, and channel-fill deposits. This paper has determined that the aggradation above the roman level is about 9 m in 1,200 years, leading an impressive average rate of 0.75 cm/year.     

What is a forest? Competing meanings and the politics of forest classification in Thung Yai Naresuan Wildlife Sanctuary, Thailand

Based on a case study in a Thai forest reserve, this article compares two modes of ‘reading’ the forest - official and local forest classification systems - and discusses how they imply different ideas about the forest, and how these competing knowledges interact with the politics of forest governance. Forest classification conventions are shown to slip, as ‘facts’ about the forest, from their origins in extraction-oriented forestry to the realm of conservation. Through a comparison of conventional vegetation classifications used in the state’s governance of the Thung Yai Naresuan Wildlife Sanctuary in Thailand, with the classificatory systems of resident Pwo Karen communities, this paper examines the slippage of conventional classifications through various uses and the emphases placed by competing representations of the forest within the context of conservation politics in Thailand. It was found that conventional classifications continued to prioritise the silvicultural potential of trees within a conservation context, downplaying other notions of forests - such as their importance to livelihoods and as lived spaces - which are present in Karen classifications.     

Improving school children’s understanding of water scarcity with a co-produced book on groundwater in Central Chile

Water scarcity is a critical issue worldwide, and Chile is no exception. Since 2010, Central Chile has been enduring an ongoing water crisis due to the coupled effects of a severe drought and the overuse of water resources, especially groundwater. Rural communities have been strongly impacted, mainly because wells from which drinking water is supplied show a dramatic drop in water levels, and some have even dried up. The water scarcity scenario requires the integration of actors and disciplines to increase awareness of groundwater; however, how to make this valuable element visible in society is an issue that remains open to debate. This paper describes and reflects on the process of making educational material about groundwater and water scarcity for children to promote public awareness. Based on transdisciplinary and co-designing processes, this work describes the social perceptions of groundwater among children and community leaders, as well as how scientific information and local knowledge of water scarcity could be integrated into a book for the young population. This research finds that educational projects on groundwater resources increase people’s awareness of the role of this hidden resource in the water cycle. Such projects encourage the creation of grounded and contextualised materials that incorporate the knowledge and experience already present in the communities, increasing public awareness of the role of groundwater and associated water scarcity issues, thereby integrating academia and society. This approach could be a tool to lay the foundations for successfully addressing the water crisis in Chile over generations.

     

Effects of illumination functions on the computation of gravity-dependent signal path variation models in primary focus and Cassegrainian VLBI telescopes

This paper sets the rules for an optimal definition of precise signal path variation (SPV) models, revising and highlighting the deficiencies in the calculations adopted in previous studies and improving the computational approach. Hence, the linear coefficients that define the SPV model are rigorously determined. The equations that are presented depend on the dimensions and the focal lengths of the telescopes as well as on the feed illumination taper. They hold for any primary focus or Cassegrainian very long baseline interferometry (VLBI) telescope. Earlier investigations usually determined the SPV models assuming a uniform illumination of the telescope mirrors. We prove this hypothesis to be over-simplistic by comparing results derived adopting (a) uniform, (b) Gaussian and (c) binomial illumination functions. Numerical computations are developed for AZ-EL mount, 32 m Medicina and Noto (Italy) VLBI telescopes, these latter being the only telescopes which possess thorough information on gravity-dependent deformation patterns. Particularly, assuming a Gaussian illumination function, the SPV in primary focus over the elevation range [0°, 90°] is 10.1 and 7.2 mm, for Medicina and Noto, respectively. With uniform illumination function the maximal path variation for Medicina is 17.6 and 12.7 mm for Noto, thus highlighting the strong dependency on the choice of the illumination function. According to our findings, a revised SPV model is released for Medicina and a model for Noto is presented here for the first time. Currently, no other VLBI telescope possesses SPV models capable of correcting gravity-dependent observation biases.     

LIDAR monitoring of mass wasting processes: The Radicofani landslide, Province of Siena, Central Italy

The Radicofani Basin, stretching about 30 km NW–SE, is an intra-Central Apennine basin connected to Pliocene–Pleistocene extensional tectonics. It consists of an Early to Middle Pliocene succession including essentially shelf pelites. In the Radicofani area, province of Siena (Tuscany region), morphodynamic processes are very frequent with widespread badlands and rapidly evolving mudflows. In order to evaluate the general instability of the Radicofani area, geological and geomorphological surveys were carried out. The 1954, 1990 and 2003 aerial surveys allowed a comparison of the changes in the various morphological aspects of the study area, which suggested an increase in slope instability with time. A new complex translational landslide evolving into mudflows, activated during the winter of 2003, was monitored using an experimental system based on terrestrial LIDAR (Light Detection and Ranging) and GPS (Global Positioning System) technologies. This system allowed the monitoring of the morphologic and volumetric evolution of the landslide. A comparison of the monitoring data of October 2004, June 2005, May 2006 and May 2007 points out that the evolution is characterised by the sliding of displaced materials. A volume of about 1300 m³ of materials was removed during the period 2004–2005, 300 m³ for 2005–2006, and 400 m³ for 2006–2007. The greater initial mass movement probably reflects a greater static imbalance during the early period of landslide movement and increased rainfall. Therefore, the proposed monitoring system methodology allows the numerical evaluation of the landslide morphological evolution and to validate the landslide evolution model based on geological and geomorphological field surveys.