Freeze, thaw, fracture?

Why does freezing break up rock? Everybody knows that when water freezes it expands by nine percent to be precise. If it seeps into rocks and then freezes, the rocks can fracture and split apart, a process known as frost weathering. So far so logical. But this long-held explanation is probably not very significant in nature because it requires some pretty unusual conditions. The rock must essentially be water-saturated and frozen from all sides, to prevent the piston-like effect of freezing water driving the remaining liquid water into empty spaces or out of the rock through an unfrozen side or crack. So we need to look for another explanation

Cruise Report: CD149 – RRS Charles Darwin 18th July to 6th August, 2003. Spreading-ridge geometry, hydrothermal activity, and the influence of modern and ancient hotspots on the Carlsberg Ridge - northwestern Indian Ocean

Cruise CD149 on board the RRS Charles Darwin aimed to explore the Carlsberg Ridge, Northern Indian Ocean. The cruise recovered multibeam swath bathymetry (EM12), dredge samples from 20 stations, water column profiles from 16 stations and water samples from one station, between 57 and 61.5°E. The initial results were: a discovery of a hydrothermal super plume – a plume signal rising 1200m above the seafloor and extending 30km along the ridge crest (named by the ship’s company as the iGass Plume); recovery of an extinct hydrothermal site with oxidised sulphide chimney fragments; imagery of a megamullion site with recovery of dolerite, flazer gabbro and moderately fresh peridotite from a core complex of lower crust and upper mantle; and fresh basaltic glass samples from 95% of the sites sampled.Until this cruise, the western Carlsberg Ridge was almost unknown, with only two or three poorly located rock samples, no continuous bathymetry, only a few single-track geophysics lines and no exploration for hydrothermal activity. However, the ridge is important since it probably includes the unradiogenic end-member of the Indian Ocean mantle source (at its eastern end), is likely to have a distal influence from the Afar hotspot (at its western end), and has a history of recent changes in spreading geometry reflected in an unusual segmentation pattern. It also represents a distal portion of the midocean ridge system that is connected through its eastern end only, thus having significant implications for the dispersal and colonisation of hydrothermal ecosystems

Cruise Report: CD149 – RRS Charles Darwin 18th July to 6th August, 2003. Spreading-ridge geometry, hydrothermal activity, and the influence of modern and ancient hotspots on the Carlsberg Ridge - northwestern Indian Ocean

Cruise CD149 on board the RRS Charles Darwin aimed to explore the Carlsberg Ridge, Northern Indian Ocean. The cruise recovered multibeam swath bathymetry (EM12), dredge samples from 20 stations, water column profiles from 16 stations and water samples from one station, between 57 and 61.5°E. The initial results were: a discovery of a hydrothermal super plume – a plume signal rising 1200m above the seafloor and extending 30km along the ridge crest (named by the ship’s company as the iGass Plume); recovery of an extinct hydrothermal site with oxidised sulphide chimney fragments; imagery of a megamullion site with recovery of dolerite, flazer gabbro and moderately fresh peridotite from a core complex of lower crust and upper mantle; and fresh basaltic glass samples from 95% of the sites sampled.Until this cruise, the western Carlsberg Ridge was almost unknown, with only two or three poorly located rock samples, no continuous bathymetry, only a few single-track geophysics lines and no exploration for hydrothermal activity. However, the ridge is important since it probably includes the unradiogenic end-member of the Indian Ocean mantle source (at its eastern end), is likely to have a distal influence from the Afar hotspot (at its western end), and has a history of recent changes in spreading geometry reflected in an unusual segmentation pattern. It also represents a distal portion of the midocean ridge system that is connected through its eastern end only, thus having significant implications for the dispersal and colonisation of hydrothermal ecosystems

Becoming Rasuwa Relief: Practices of Multiple Engagement in Post-Earthquake Nepal

In this article, we reflect on the multiple nature of our engagements in the wake of the 7.8m earthquake that struck Nepal on April 25th 2015. Specifically, we trace the events, experiences, decisions, positions, and processes that constituted our work with a post-earthquake volunteer initiative we helped to form, called Rasuwa Relief. Using the concept of multiplicity (cf. Mol 2002), we consider the uncertain process by which Rasuwa Relief began to cohere, as a collective of diverse efforts, interventions, projects, and commitments, and how Rasuwa Relief was continually and multiply enacted through practices of engagement. As a collaborative effort that coordinated and consolidated many of our post-earthquake interventions over a period of two years, Rasuwa Relief was always in a state of becoming. This process of becoming, we suggest, indexed and informed the multiple ways that we participated and intervened in the aftermath of the earthquake—as accidental humanitarians or ‘relief workers’, as early-career scholars, and as people attempting to balance diverse personal, academic, and ethical commitments within and beyond Nepal. Based on a reflexive analysis of these multiple engagements, we also present an embedded critique of ‘humanitarian reason’ (Fassin 2012), inclusive of our own decisions and actions, alongside a selfcritical analysis of the affective factors that shaped our own ‘need to help’ (Malkki 2015)

The chronostratigraphy of Late Pleistocene glacial and periglacial aeolian activity in the Tuktoyaktuk Coastlands, NWT, Canada

Aeolian periglacial sand deposits are common in the Tuktoyaktuk Coastlands of Western Arctic Canada. Regionally extensive and thick aeolian sand-sheet deposits have been observed in two major stratigraphic settings: within a sand unit characterized by large aeolian dune deposits; and interbedded with glaciofluvial outwash from the Laurentide Ice Sheet (LIS). Small, localized sand sheets have also been observed along the tops of sandy bluffs, within sequences of drained thermokarst lakes deposits and as an involuted veneer above buried basal ice of the LIS. On the basis of radiocarbon and optically stimulated luminescence (OSL) dates from preserved periglacial aeolian sand sheets and dunes a regional chronostratigraphy is presented which indicates that both extensive dunes and sand sheets accumulated mainly between ca 30 and 13 ka. A switch to dominantly sand-sheet aggradation at ca 14–13 ka, with sand sheets forming widely until ca 8 ka, is attributed to (a) surface armouring by glacial deposits associated with the advance of the LIS; and (b) amelioration of the climate from cold aridity. An absence of OSL dates between ca 8 and 1 ka suggests that sand sheets stabilized during much of the Holocene. Local sand-sheet aggradation during recent centuries has occurred near sandy bluffs and on the floors of drained thermokarst lakes. The OSL dates constrain the maximum extent of the LIS in the Tuktoyaktuk Coastlands to Marine Isotope Stage 2

Profiling the Quality of End of Life Care

ABSTRACT Despite increased national debate regarding quality of life and quality of care at the end of life, patients in the United States continue to die primarily in hospitals experiencing a myriad of distressing symptoms, leaving caregivers and healthcare professionals wondering if caring for the dying will ever change in this country. There are alternatives available, but it is necessary to assess current conditions for dying patients in order to change the status quo in end of life care. Profiling how patients experience the last few months of life, as well as their terminal hospital stay, is a starting point for just such an assessment. The following manuscript outlines the purpose of profiling dying populations and provides a framework for compiling profile data for patients who expire in an institutional setting. Utilizing Myra Levine\u27s four conservation principles of nursing care, the following study examines quality indicators identified for end of life care and discusses these domains with regard to specific decline-to-death disease trajectory groups identified in the study