Surtseyan style eruption in the Ambae (Vanuatu,New Hebrides) caldera lake in 2005 December and its implication to volcanic hazards and emergency management on an ocean island.

No abstract availabl

Lava lakes and shallow level magmatic feeding systems of mafic volcanoes of an ocean island: Ambrym, Vanuatu (New Hebrides), South Pacific

Ambrym is an active volcanic island with 2 major vent complexes; Marum and Benbow. These vent complexes are continuously active over at least the past two thousands of years. These active vents either produce constant degassing during quite periods or sub-Plinian to Vulcanian explosive eruptions commonly influenced by magma-water interaction triggered phreatomagmatic explosive phases. The active vents of Ambrym perfectly expos inner walls of the crater/conduit transition zone, allowing to study in cross sectional view of the interbedded coherent magmatic bodies with pyroclastic successions. In the inner crater/conduit wall of the Marum volcano, that consists of at least 3 major vents, as well as a vent that is located on its flank (Niri Taten) exposes solidified complex lava lake cross-sections, lava spatter cone feeding lava pods, shallow intrusions as well as large sills that connected through a complex network of pathways to the surface and/or into the pyroclastic edifice of the volcano. This suggests that shallow level infiltration of melt into a mafic volcano plays an important role in the edifice growth

Syn- and post-eruptive erosion, gully formation, and morphological evolution of a tephra ring in tropical climate erupted in 1913 in West Ambrym, Vanuatu

Syn- and post-eruptive erosion of volcanic cones plays an important role in mass redistribution of tephra over short periods. Descriptions of the early stages of erosion of tephra from monogenetic volcanic cones are rare, particularly those with a well-constrained timing of events. In spite of this lack of data, cone morphologies and erosion features are commonly used for long-term erosion rate calculations and relative age determinations in volcanic fields. Here we provide new constraints on the timing and nature of erosion from a tephra ring erupted in 1913 in West Ambrym, Vanuatu and exposed along a continuous 2.5 km long coastal section. The ring surrounds an oval shaped depression filled by water. It is composed of a succession of a phreatomagmatic fall and base surge beds, interbedded with thin scoriaceous lapilli units. Toward the outer edges of the ring, base-surge beds are gradually replaced in the succession by fine-ash dominated debris-flows and hyperconcentrated-flow deposits. The inter-fingering of phreatomagmatic deposits with syn-volcanic reworked volcaniclastic sediments indicates an ongoing remobilisation of freshly deposited tephra already during the eruption. Gullies cut into the un-weathered tephra are up to 4 m deep and commonly have c. 1 m of debris-flow deposit fill in their bases. There is no indication of weathering, vegetation fragments or soil development between the gully bases and the basal debris flow fills. Gully walls are steep and superficial fans of collapsed sediment are common. Most gullies are heavily vegetated although some active (ephemeral) channels occur. Hence, we conclude that the majority of the erosion of such tephra rings in tropical climates takes place directly during eruption and possibly for only a period of days to weeks afterward. After establishment of the gully network, tephra remobilisation is concentrated only within them. Therefore the shape of the erosion-modified volcanic landform is predominantly developed shortly after the eruption ceases. This observation indicates that gully erosion morphology may not necessarily relate to age of such a landform. Different intensities of erosion during eruption (related to water supply or rainfall) are probably the major influence on gully spacing, modal depth and form. Longer-term post-eruption processes that could be indicators of relative age may include internal gully deepening (below basal debris-flow fill sediments) and possibly widening and side-slope lowering due to undercutting and side-collapse

Samoa technical report - Review of volcanic hazard maps for Savai'i and Upolu

Both main islands of Samoa, Savai'i and Upolu need to be considered as potentially volcanically active. The most recent eruptions in historic times happened on Savai'i in 1905-1911, 1902 and 1760 (estimated). Though detailed volcanic studies and dating of volcanic events are very limited there is evidence for repeated volcanic activity on both islands since the time of human occupation of the islands marked by prominent and fresh appearance of tuff cones as Tafua (= fire mountain) Savai'i, the island of Apolima, Tafua Upolu and offshore Cape Tapaga. This report examines the volcanic risks for both islands and defines for disaster management considerations potential eruption scenarios based on eyewitness accounts of previous eruptions, geological field evidence, remote sensing information and experiences from similar volcanoes. A detailed timeline of events, potential impacts and required emergency response activities are listed for the five potential eruption types (1) long-term lava field (2) short-term spatter-cone (3) explosive phreatomagmatic (4) explosive scoria-cone and (5) submarine flank collapse. Given the nature of volcanism in Samoa with hundreds of individual "one-off" volcanoes scattered along zones of structural weakness within the Savai'i - Upolu Platform - predicting the exact location of future eruption centres is impossible. At the current stage of knowledge a presentation of a volcanic hazard map is inadequate and would require additional baseline studies to statistically define recurrence intervals and areas of higher volcanic activity. Taking these limitations into account, maps showing the relative potential for new eruption vents on Upolu and Savai'i are derived from geomorphologic features. To improve our understanding and management of the volcanic risks of Samoa, suggestions for achievable future work are listed and prioritised. These recommendations include geological/volcanological baseline studies (e.g. dating/detailed analyses of past events, rock chemistry, volcano structure); installation of early warning and monitoring network (e.g. permanent GPS, seismometers); and disaster preparedness and volcanic crisis response planning

Promoting phantasmal tourism for America’s ‘roads to hell’ could help drive rural economic development

With increasing concerns about the economic and environmental impacts of traditional mass-tourism, ‘niche’ destination’ tourism is becoming an increasingly popular alternative. David J. Nemeth looks at ‘phantasmal’ tourism, which attracts visitors to experience imagined supernatural, magical, or mystical allure. He argues that by capitalizing on the perceived ‘dark’ aspects of roadways numbered 666 authorities in America can encourage tourism and development to revitalize depressed local economies

Operation of hydrodynamic journal bearings in sodium at temperatures to 800 deg F and speeds to 12000 rpm

Operation of hydrodynamic journal bearings in liquid sodium at high temperatures and high speed

Exploding lakes in Vanuatu - "Surtseyan-style" eruptions witnessed on Ambae Island

After a long silence, Lake Vui on Ambae Island burst into spectacular life on the 28th of November 2005, disrupting the lives of 10 000 inhabitants on this sleepy tropical island in the SW Pacific. "Surtseyan- style" explosions burst through the Island's summit lake waters forming a new tuff-cone and threatening to form deadly lahars or volcanic floods. Such eruptions are rarely well observed, and these fleeting opportunities provide a chance to match volcanic processes with rock-sequences found commonly in the geologic recor

The impact of gruesome evidence on mock juror decision making : the role of evidence characteristics and emotional response

Two experiments were conducted to investigate the effects of gruesome evidence on mock jurors? decisions in a simulated capital trial. The first experiment was designed as a replication and extension of Douglas, Lyon, and Ogloff (1997), who found that mock jurors who were presented with gruesome photographic evidence were nearly twice as likely to convict the defendant than participants who did not see the gruesome evidence. In Experiment 1, gruesome evidence was manipulated in two ways: photographic evidence (low gruesome, highly gruesome, or control photographs) and verbal testimony (low gruesome vs. highly gruesome). Neither photographic evidence nor testimony had an effect on mock jurors verdicts or sentence decisions. However, the manipulation check failed to indicate that participants perceived the evidence differently in terms of gruesomeness. Experiment 2 was designed to address whether inducing specific emotions in participants would produce similar biasing effects on their decisions as gruesome evidence. Previous research has eluded to emotional arousal as a potential mediator of the effects of gruesome evidence. Participants were induced to feel either angry or sad and were compared to participants who were given a neutral-emotion induction and viewed either low or highly gruesome photographs. The results indicated that neither emotion nor gruesome photographic evidence had an effect on participants? verdicts. However, participants? who viewed highly gruesome photographic evidence were more likely to decide on the death sentence than participants who viewed the low gruesome evidence. The results are discussed in light of the previous research on gruesome evidence and theories of emotion and decision making

Update And Guidance On Management Of Myopia. European Society Of Ophthalmology In Cooperation With International Myopia Institute

Authors: J. Nemeth, B. Tapaszto, W. Aclimandos, Ph. Kestelyn, J. Jonas, J-T. De Faber, I. Januleviciene, A. Grzybowski, Z. Zsolt Nagy, O. Parssinen, J. Guggenheim, P. Allen, R. Baraas, K. Saunders, D. Flitcroft, L. Gray, J. Polling, A. Haarman, J. Tideman, J. Wolffsohn, S. Wahl, J. Mulder, I. Smirnova, M Formenti, H. Radhakrishnan, S. ResnikoffThe prevalence of myopia is increasing extensively worldwide. The number of people with myopia in 2020 is predicted to be 2.6 billion globally, which is expected to rise up to 4.9 billion by 2050, unless preventive actions and interventions are taken. The number of individuals with high myopia is also increasing substantially and pathological myopia is predicted to become the most common cause of irreversible vision impairment and blindness worldwide and also in Europe. These prevalence estimates indicate the importance of reducing the burden of myopia by means of myopia control interventions to prevent myopia onset and to slow down myopia progression. Due to the urgency of the situation, the European Society of Ophthalmology decided to publish this update of the current information and guidance on management of myopia. The pathogenesis and genetics of myopia are also summarized and epidemiology, risk factors, preventive and treatment options are discussed in details

The orbits of subdwarf-B + main-sequence binaries. II. Three eccentric systems; BD+29 3070, BD +34 1543 and Feige 87

The predicted orbital-period distribution of the subdwarf-B (sdB) population is bi-modal with a peak at short ( 250 days) periods. Observationally, many short-period sdB systems are known, but the predicted long period peak is missing as orbits have only been determined for a few long-period systems. As these predictions are based on poorly understood binary-interaction processes, it is of prime importance to confront the predictions with reliable observational data. We therefore initiated a monitoring program to find and characterize long-period sdB stars. In this paper we aim to determine the orbital parameters of the three long-period sdB+MS binaries BD+29 3070, BD+34 1543 and Feige 87, to constrain their absolute dimensions and the physical parameters of the components. High-resolution spectroscopic time series were obtained with HERMES at the Mercator telescope on La Palma, and analyzed to determine the radial velocities of both the sdB and MS components. Photometry from the literature was used to construct the spectral-energy distribution (SED) of the binaries. Atmosphere models were used to fit these SEDs and to determine the surface gravities and temperatures of both components of all systems. Spectral analysis was used to check the results of the SEDs. An orbital period of 1283 +- 63 d, a mass ratio of q = 0.39 +- 0.04 and a significant non-zero eccentricity of e = 0.15 +- 0.01 were found for BD+29 3070. For BD+34 1543 we determined P = 972 +- 2 d, q = 0.57 +- 0.01 and again a clear non-zero eccentricity of e = 0.16 +- 0.01. Last, for Feige 87 we found P = 936 +- 2 d, q = 0.55 +- 0.01 and e = 0.11 +- 0.01. BD+29 3070, BD+34 1543 and Feige 87 are long period sdB + MS binaries on clearly eccentric orbits. These results are in conflict with the predictions of stable Roche-lobe overflow models.Comment: 15 pages, 6 figures, Accepted by A&