9,126 research outputs found
The application of regional-scale geochemical data in defining the extent of aeolian sediments : the Late Pleistocene loess and coversand deposits of East Anglia, UK
The âEuropean Coversand Sheetâ is a discontinuous âsheetâ of aeolian
(windblown) loess and coversand that extends through eastern and
southern England, across the English Channel into northern France,
Belgium and the Netherlands (Kasse, 1997; Antoine et al., 2003). Whilst
some of the earlier aeolian sediments date from the Middle
Pleistocene, most correspond to the Late Pleistocene Weichselian /
Devensian and earliest Holocene stages. East Anglia contains
considerable accumulations of aeolian sediment. Although several
valuable studies have attempted to determine the spatial extent of
aeolian material (e.g. Catt, 1977, 1985), defining their margins has
proved largely difficult because aeolian material is highly susceptible to
reworking and removal by various natural and anthropogenic agents.
Within this study, we use regionalâscale geochemical data from
soils to reconstruct the extent of aeolian sediments in East Anglia. A
specific geochemical signature, defined by elevated concentrations of
Hafnium (Hf) and Zirconium (Zr), is strongly characteristic of soils
developed on aeolian deposits within the United States, China, Europe
and New Zealand (Taylor et al., 1983). The data suggests that the
approach is sufficiently sensitive to identify a residual aeolian
component within soils even where deposits may be thin and unmappable
by conventional methods, or if the material has been largely
eroded
Outwash sedimentation and glacitectonic deformation during accretion of the Cromer Ridge: evidence from Holt, north Norfolk, UK
Sections through sand and gravel deposits exposed by aggregate extraction provide further evidence for the development of a complex proglacial / ice-marginal meltwater drainage system during the Anglian Glaciation. Their sedimentology indicates that deposition occurred within a series of anastomosing braided river channels â interpreted as background sedimentation, punctuated by
episodes of elevated discharge characterised by unconstrained sheet-flow. Meltwater sediments form part of an extensive (albeit heavily-dissected) sandur that extends southwards from Cromer towards Norwich and developed during a temporary ice-marginal still-stand associated with the formation of the Cromer Ridge âmoraine complexâ
A review of Citizen Science within the Earth Sciences: potential benefits and obstacles
The field of citizen science is a rapidly evolving type of scientific research focussing on the collaboration of motivated volunteers (citizen scientists) with professional scientists to generate new knowledge and information. In recent years, there has been a steady growth of Earth Science related citizen science projects that aim to build knowledge, awareness and ultimately resilience to key local- to global-scale environmental issues (e.g., geohazards, environmental monitoring). In addition, there has also been progression from small pilot studies to large data collection Earth Science citizen science initiatives that are used to underpin modelling. However, despite this, numerous operational and strategic challenges exist and whilst the awareness of citizen science has improved markedly, it is clear that the direct impact of citizen science on policy and decision making is still limited. Within this paper, we review these challenges alongside defining citizen science itself, and its benefits. The range of methods and applications of citizen science are explored through a series of case studies centred on geohazards, observations & classification, multi-topic, and education/outreach. The paper also explores future citizen science opportunities within Earth Science
Parity Measurement is Sufficient for Phase Estimation at the Quantum Cramer-Rao Bound for Path-Symmetric States
In this letter, we show that for all the so-called path-symmetric states, the
measurement of parity of photon number at the output of an optical
interferometer achieves maximal phase sensitivity at the quantum Cramer-Rao
bound. Such optimal phase sensitivity with parity is attained at a suitable
bias phase, which can be determined a priori. Our scheme is applicable for
local phase estimation
Integrating physical activity data technologies into elementary school classrooms
This paper describes an iteration of a design-based research project that involved integrating commercial physical activity data (PAD) sensors, such as heart rate monitors and pedometers, as technologies that could be used in two fifth-grade classrooms. Design-based research involves the development, implementation and study of new learning interventions in real-world contexts with the goal of elaborating principles or guidelines relevant to the design of new technologies and learning experiences. The current project involved the implementation of PAD technology-supported learning activities in two fifth-grade classrooms where students pursued investigations related to the distances that they walk, the relationship between heights and footsteps taken, and variations in heart rates among twins and with adults. In addition to describing some of the practical lessons learned related to the use of PAD technologies with elementary school children, we describe our initial efforts to assess studentsâ knowledge before and after the learning intervention. Results from the written assessments indicated that the newly designed activities indeed covered the intended content related to measures of center and averages. Results from the interviews suggested that students who participated in the unit designed to incorporate PAD technologies more reliably accessed knowledge related to measures of center and averages in scenario based problems than their counterparts who followed a traditional unit
A tectonostratigraphic scheme for glacial deposits in northern East Anglia, UK
East Anglia possesses a spectacular archive of lowland glaciation that spans the Middle and Late Pleistocene and links the region to ice masses that repeatedly glaciated central and eastern Britain and the North Sea region. Attempts to develop a stratigraphic framework for this archive have typically utilised conventional lithostratigraphic approaches and a range of different nomenclatures and schemes have been presented over the years. However, these lithostratigraphic approaches contain a number of inherent flaws that limit their applicability. Firstly, the process of glaciation is driven largely by âtectonicâ rather than âsedimentaryâ mechanisms such that glacigenic sequences do not always obey the Law of Superposition. Secondly, glacigenic units do not always possess distinct and spatially-extensive lithostratigraphic characteristics because glaciers can flow-over, erode and entrain a wide range of substrate lithologies. Thirdly, ice advances do not always result in the deposition of a till but can simply override and glacitectonically-deform an underlying sediment-pile. In East Anglia, all of these issues manifest themselves to varying degrees, such that published lithostratigraphic schemes typically underestimate the number of ice advances and ice-marginal oscillations within the geological record. Within this paper, we present a hybrid tectonostratigraphic classification for the glacial succession of northern East Anglia, encompassing where appropriate, lithostratigraphic and morphostratigraphic elements. This approach identifies seven major tectonostratigraphic sub-divisions relating to individual ice-advances and a progressive shift in tectonic regime reflecting the long-term evolution of substrate and deforming-bed processes across the region during glaciation
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