Enhancing the effectiveness of policy-relevant integrative research in rural areas

There has been much debate about the importance of policy-relevant research in geography over the last decade. There has also been an increasing recognition by policymakers of the importance of integrative (interdisciplinary and transdisciplinary) approaches to policy-relevant research. However, geographers have been more reluctant than their colleagues in other social and natural sciences to embrace integrative research collaborations. For integrative research to achieve its full potential and to encourage greater participation from the geographical research community, we need to increase our understanding of its potential value, but also some of the challenges that it poses, and how these can be overcome. In this paper, we consider the processes involved in conducting successful integrative research from the perspective of researchers involved in these projects. We base our analysis on the results of a questionnaire survey of international integrative research programmes on environmental issues in rural areas, combined with our own experiences of working in integrative research. We conclude that effective integrative research depends on the establishment of a clear conceptual framework, the use of appropriate temporal and spatial scales in the research, effective language and communication, time and commitment, and trust and respect. We also highlight the value of stakeholder involvement in integrative research to ensure the policy relevance of the work and provide a mechanism to assist with effective knowledge transfer of the results.     

Changes in direction of the remanence of rocks produced by stationary alternating field demagnetization

Summary. A theoretical investigation of the way in which an isotropic rock containing single-domain particles acquires both IRM and ARM (or TRM) has indicated that stationary single-axis alternating field (af) demagnetization with the af axis at an angle to the remanence vector should produce progressive angular changes in a single-component remanence as demagnetization proceeds. Just before the remanence is completely removed it should lie at 90° to the af axis irrespective of the original orientation of the remanence (apart from 0°). Experimental observations on a rock sample support these deductions.
This analysis has been extended to investigate the way in which ARM (or TRM) and IRM are demagnetized by static three-axis demagnetization methods which are used by some workers in palaeomagnetism. Theory, in conjunction with the use of a numerical model, predicts that an ARM or TRM should not undergo significant direction changes when these methods are applied but an IRM should undergo progressive direction changes as demagnetization proceeds, usually moving until it makes an angle of cos⁻¹ (1/3) with each of the three af axes just before it is removed. Confirmation that such changes do occur have been obtained by experiments on a rock sample. The relative merits of static and tumbling af demagnetization methods are also discussed.     

Experimental studies related to atmospheric flow around obstacles

Summary Laboratory-scale experiments on a small cylindrical barrier capable of being moved zonally with respect to a rotating hemispherical shell of liquid are described. When the cylinder is moved west relative to the shell at rates approximating 1/10 of the basic rotation a strong anticyclonic circulation developes around the cylinder and pronounced wave motions appear in the remainder of the liquid. When the cylinder is moved eastward at the same relative rates there is no net circulation around it and rapid motions toward the east occur in the latitude zone that it occupies. Velocity discontinuity surfaces on which occasional vortices develop divide this zone from the remainder of the liquid on both sides where much less developed motions occur. General implications of these and certain other types of experiments for problems of flow over large mountain masses are pointed out.     

Karrat Fjord (Greenland) tsunamigenic landslide of 17 June 2017: initial 3D observations

On 17 June 2017, a landslide-generated tsunami reached the village of Nuugaatsiaq, Greenland, leaving four persons missing and presumed dead. Here, we present a preliminary high-resolution analysis of the tsunamigenic landslide scar based on three-dimensional (3D) reconstructions of oblique aerial photographs taken during a post-failure reconnaissance helicopter overflight. Through a 3D quantitative comparison with pre-failure topography, we estimate that approximately 58 million m³ of rock and colluvium (talus) was mobilized during the landslide, 45 million m³ of which reached the fjord, resulting in a destructive tsunami. We classify this event as a “tsunamigenic extremely rapid rock avalanche,” which likely released along a pre-existing metamorphic fabric, bounded laterally by slope-scale faults. Further analysis is required to properly characterize this landslide and adjacent unstable slopes, and to better understand the tsunami generation.     

Mercury Dynamics in a San Francisco Estuary Tidal Wetland: Assessing Dynamics Using In Situ Measurements

We used high-resolution in situ measurements of turbidity and fluorescent dissolved organic matter (FDOM) to quantitatively estimate the tidally driven exchange of mercury (Hg) between the waters of the San Francisco estuary and Browns Island, a tidal wetland. Turbidity and FDOM??representative of particle-associated and filter-passing Hg, respectively??together predicted 94?% of the observed variability in measured total mercury concentration in unfiltered water samples (UTHg) collected during a single tidal cycle in spring, fall, and winter, 2005?C2006. Continuous in situ turbidity and FDOM data spanning at least a full spring-neap period were used to generate UTHg concentration time series using this relationship, and then combined with water discharge measurements to calculate Hg fluxes in each season. Wetlands are generally considered to be sinks for sediment and associated mercury. However, during the three periods of monitoring, Browns Island wetland did not appreciably accumulate Hg. Instead, gradual tidally driven export of UTHg from the wetland offset the large episodic on-island fluxes associated with high wind events. Exports were highest during large spring tides, when ebbing waters relatively enriched in FDOM, dissolved organic carbon (DOC), and filter-passing mercury drained from the marsh into the open waters of the estuary. On-island flux of UTHg, which was largely particle-associated, was highest during strong winds coincident with flood tides. Our results demonstrate that processes driving UTHg fluxes in tidal wetlands encompass both the dissolved and particulate phases and multiple timescales, necessitating longer term monitoring to adequately quantify fluxes.