A modest all-sky search for narrowband radio radiation near the 21-cm hydrogen line

Since 1973 an all-sky, full-time search for narrowband radio radiation (presumably of intelligent origin) near 21 cm has been underway at the Ohio State University Radio Observatory. The search concentrates on a band 380 kHz wide centered on the hydrogen line, corrected to the Galactic Standard of Rest. The search is limited by lack of funding and personnel. It has been found that beam switching is an important technique for reducing terrestrial interference, and that galactic hydrogen emission does not cause significant extraterrestrial interference. A number of small-diameter cold hydrogen clouds have been discovered. No confirmed narrowband extraterrestrial signals have been found between +48° and +14° in declination above the detection limit of 1.5 × 10^?21 W/m².     

Near–surface ground temperature regime variability in selected microenvironments, Kärkevagge, Swedish Lapland

The importance of topographic microvariability in influencing shallow (10–50 cm depths) soil temperature regimes in arctic–alpine Kärkevagge, northern Sweden, from August 1999 to July 2000 is demonstrated using six sites. The ground microclimate on the tops of very large boulders forming an extensive boulder field in the central valley bottom is more comparable to that at an alpine ridge–crest site 300 m higher than it is to the microclimate at the base of one of the boulders. The boulder crests also differ substantially from the more generalized valley–bottom conditions outside the boulder field. Assuming that chemical processes may be active at temperatures at or above 0°C, sites in the valley experience favorable conditions from 159 to 324 days of the year. Aside from the annual cycle, freeze–thaw cycles are infrequent within Kärkevagge.     

The ordovician (caradoc) volcanic rocks of montgomery,Powys, N. Wales

The Ordovician (Caradoc, Soudleyan) rocks of Montgomery, Powys are shales interbedded with locally conglomeratic volcaniclastic sediments composed of andesitic detritus. New formal lithostratigraphic units are proposed: Montgomery Volcanic Group comprising in ascending order: Castle Hill Shale Formation, Castle Hill Conglomerate Formation and Quarry Sandstone and Shale Formation. The volcaniclastic strata are reinterpreted as deposits of a submarine volcaniclastic fan system sourced by contemporaneous andesitic island volcanism. The observed diagenetic sequence is typical of marine volcanic sandstones and was dominated by hydration reactions related to the degradation of abundant unstable volcanic detritus. Diagenesis has resulted in the virtual destruction of original porosity in the volcaniclastic rocks.     

Mercury concentrations in stomach contents and muscle of five fish species from the north east coast of England

Mercury concentrations in stomach contents and muscle tissue are reported for five fish species: herring (Clupea harengus), whiting (Merlangius merlangus), roker (Raja clavata), plaice (Pleuronectes platessa) and dab (Limanda limanda) collected in summer 1992 off the mouth of the River Tyne, North East England. Median muscle mercury concentrations in the area increase in the order plaice < herring < roker < dab < whiting. Absolute mercury concentrations and muscle mercury-length relationships indicate that the environmental availability of mercury in the study area is low. Stomach contents were recovered from dab, plaice and roker only. Median mercury concentrations in stomach contents increased in the order plaice < roker < dab. The variability of the ratio (muscle mercury/stomach content mercury) has been examined for these three species. In dab the variation is relatively low (39.7% RSD), whereas in plaice and roker it is considerably higher (128.4% and 184.6%, respectively). If stomach content mercury concentrations accurately reflect local mercury availability then dab muscle tissue would make a more reliable availability index than muscle tissue of plaice or roker.     

Aeolian Sky packaged chemicals pollution incident

Three and a half thousand packages of chemicals, including at least 956 containing hazardous substances were washed ashore on to the beaches of southern England. They were believed at the time to have come from the wreck of the Aeolian Sky. There is now a strong suspicion that half the packages, including 32 canisters of arsenic trichloride, were lost from the deck cargo of another vessel in the English Channel. Despite difficulties in identifying the contents of many unlabelled chemical packages found on the shore, most were recovered during clearance operations by Local Authorities. Although there was no evidence of any ecological damage, 20 people were taken to hospital for treatment or precautionary medical examinations following contact with opened or leaking packages. This incident raised questions regarding international reporting procedures, liability and compensation arrangements following losses of packaged chemical cargoes at sea.     

Lava bubble-wall fragments formed by submarine hydrovolcanic explosions on Lō'ihi Seamount and Kīlauea Volcano

 Glassy bubble-wall fragments, morphologically similar to littoral limu o Pele, have been found in volcanic sands erupted on Lō'ihi Seamount and along the submarine east rift zone of Kīlauea Volcano. The limu o Pele fragments are undegassed with respect to H₂O and S and formed by mild steam explosions. Angular glass sand fragments apparently form at similar, and greater, depths by cooling-contraction granulation. The limu o Pele fragments from Lō'ihi Seamount are dominantly tholeiitic basalt containing 6.25–7.25% MgO. None of the limu o Pele samples from Lō'ihi Seamount contains less than 5.57% MgO, suggesting that higher viscosity magmas do not form lava bubbles. The dissolved CO₂ and H₂O contents of 7 of the limu o Pele fragments indicate eruption at 1200±300 m depth (120±30 bar). These pressures exceed that generally thought to limit steam explosions. We conclude that hydrovolcanic eruptions are possible, with appropriate pre-mixing conditions, at pressures as great as 120 bar. Received: 22 December 1998 / Accepted: 16 July 1999     

Appropriate aspirations for effective post-mining restoration and rehabilitation: a response to Kaźmierczak et al.

Confusion surrounding the definition and application of terminology in post-mining ecological repair has resulted in uncertainty for industry, the scientific community and regulators. This lack of clarity may underrepresent high aspirations or could be misused to disguise low aspirations and so is problematic for setting objectives, establishing goals and assessing recovery trajectories. We respond to a recently published analysis of the ecosystem repair literature, where we highlight inconsistencies stemming from inadequate reference to a large proportion of the restoration and rehabilitation literature. We outline increasingly well-accepted and internationally applied definitions concerning the restoration and recovery process and invite both the mining industry and policy-makers to re-examine their terminology in the interests of attaining an internationally agreed nomenclature. Clarity in the use and understanding of terminology will align post-mining targets with community expectation, enhance the capacity of the mining industry to understand and meet these targets, and foster better analysis and more industry-relevant discussion of recovery methodologies by the scientific community and practitioners.     

An acoustic emission landslide early warning system for communities in low-income and middle-income countries

Early warning systems for slope instability are needed to alert users of accelerating slope deformation behaviour, enable evacuation of vulnerable people, and conduct timely repair and maintenance of critical infrastructure. Communities exposed to landslide risk in low- and middle-income countries seldom currently instrument and monitor slopes to provide a warning of instability because existing techniques are complex and prohibitively expensive. Research and field trials have demonstrated conclusively that acoustic emission (AE) monitoring can be an effective approach to detect accelerating slope movements and to subsequently communicate warnings to users. The objective of this study was to develop and assess a simple, robust, low-cost AE monitoring system to warn of incipient landslides, which can be widely deployed and operated by communities globally to help protect vulnerable people. This paper describes a novel AE measurement sensor that has been designed and developed with the cost constrained to a few hundred dollars (US). Results are presented from physical model experiments that demonstrate performance of the AE system in measuring accelerating deformation behaviour, with quantifiable relationships between AE and displacement rates. Exceedance of a pre-determined trigger level of AE can be used to communicate an alarm to users in order to alert them of a slope failure. Use of this EWS approach by communities worldwide would reduce the number of fatalities caused by landslides.     

CHEMICAL WEATHERING PROCESSES ON THE VANTAGE PEAK NUNATAK,JUNEAU ICEFIELD,SOUTHERN ALASKA

On the Vantage Peak nunatak in the Juneau Icefield of southeastern Alaska, grus and soils display evidence of extensive chemical alteration in a self-evidently periglacial environment. Accompanying the alteration of bedrock to grus and soil is a decrease in grain size. Grus is dominated by very coarse sand while the soils are predominantly fine sand. Grain-size reduction is attributed primarily to mineral grain dissolution. Total chemical analyses show that alkali earths (calcium and magnesium) and alkalis (sodium and potassium) are lost as weathering progresses, while silicon and iron increase relative to resistant elements. Secondary clay minerals present in the grus and soils appear to have been derived from clay-size primary minerals. Vermiculite is the principal secondary clay mineral and appears to have formed by the alteration of biotite. Scanning electron microscopy shows that quartz and feldspars are primarily weathered by dissolution with no evidence of feldspar transformation to secondary clays. Superimposed on these weathering transformations is evidence of eolian processes. Chemical weathering processes, notably dissolution and clay mineral transformation, do occur in the periglacial environment of the Vantage Peak nunatak and are clearly an important component of the periglacial geomorphic process suite.