32 research outputs found
Teaching practical science online using GIS: a cautionary tale of coping strategies
Strong demand for GIS and burgeoning cohorts have encouraged the delivery of GIS teaching via online distance education models. This contribution reviews a brief foray (2012â2014) into this field by the Open University, deploying open source GIS software to enable students to perform practical science investigations online. The âRemote observationâ topic spanned four science disciplines in 6 weeks â an ambitious remit within an innovative overarching module. Documenting the challenges and strategies involved, this paper uses forum usage and student feedback data to derive insights into the student experience and the pitfalls and pleasures of teaching GIS at a distance
New Ar-Ar ages of southern Indian kimberlites and a lamproite and their geochemical evolution
The kimberlites and lamproites of southern India are thought to have formed in the most prolific known period of Precambrian ultramafic/ultrapotassic magmatism at around 1100 Ma. This study reports new age data for southern Indian ultrapotassic rocks (kimberlites and lamproites), a controversial topic due to the wide range of published age data and disagreements over the reliability of previously published ages. In this study we obtained new high-precision ArâAr data that better constrain the ages of southern Indian ultrapotassic rocks. Dates from three samples are presented, including two kimberlites from Wajrakarur kimberlite field and one lamproite from the Krishna lamproite field. These age data are then combined with bulk-rock geochemical and Nd isotopic data to provide further constraints on the source region and primary magma composition of southern Indian kimberlites and lamproites. Previously, the Chelima lamproite (ca. 1400 Ma) was considered to be one of the oldest lamproites in the world. However, our age data suggest that at least one lamproite (Pochampalle) was generated in the same region 100 Ma before the Chelima event. The Pochampalle lamproite was emplaced around ~1500 Ma as shown by the ArâAr data in this study, roughly 250 Ma before the other Krishna lamproites. It would seem that the Pochampalle lamproite was also derived from an isotopically distinct source region with a lower 143Nd/144Nd ratio than other lamproites in the Krishna field. These findings not only have implications for regional ultramafic/ultrapotassic magmatism, but also demonstrate that the mantle processes for producing lamproitic melts existed earlier than previously thought
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3D virtual geology field trips: opportunities and limitations
As a part of The OpenScience Laboratory, (http://www.open.ac.uk/blogs/openscience/), an initiative of The Open University (OU) and The Wolfson Foundation, we are developing a 3D simulation of a Geology field trip based around Skiddaw in the Lake District, using the Unity 3D software (http://unity3d.com/). We are using digital data and imagery to reconstruct the landscape faithfully enough to provide a real sense of presence for the user.
The application will be based around a 10km x 10km low/medium detail model of the terrain and LiDAR data around Skiddaw, with overlaid aerial photography, and including walls, trees, buildings etc.
The Skiddaw field trip in the Lake District is an integral part of Earth science teaching at the OU; students carry out a real field trip and can also learn about it through DVD activities. The primary objective of developing an authentic 3D interactive simulation has been to provide an immersive experience to the users through sense of space. The virtual embodiment in the form of avatars and the multi-user environment will help give a sense of co-presence and provide opportunities for collaborative learning. The interactions and the learning activities within the 3D environment are designed to mirror the experience of a real field trip.
We aim to have an operational 3D virtual geology trip by the time of the Conference in April 2013. During the workshop and through demonstration of the 3D field trip, we plan to address: comparison of the 3D experience with 2D virtual field trips; the role that a 3D virtual geology field trip can play in terms of preparation and reflection before and after a real field trip; and whether and how a 3D simulation helps in gaining geological fieldwork skills and what are the limitations of 3D virtual geology field trips
Garnetâmonazite rare earth element relationships in sub-solidus metapelites: a case study from Bhutan
A key aim of modern metamorphic geochronology is to constrain precise and accurate rates and timescales of tectonic processes. One promising approach in amphibolite and granulite-facies rocks links the geochronological information recorded in zoned accessory phases such as monazite to the pressureâtemperature information recorded in zoned major rock-forming minerals such as garnet. Both phases incorporate rare earth elements (REE) as they crystallize and their equilibrium partitioning behaviour potentially provides a useful way of linking time to temperature. We report REE data from sub-solidus amphibolite-facies metapelites from Bhutan, where overlapping ages, inclusion relationships and Gd/Lu ratios suggest that garnet and monazite co-crystallized. The garnetâmonazite REE relationships in these samples show a steeper pattern across the heavy (H)REE than previously reported. The difference between our dataset and the previously reported data may be due to a temperature-dependence on the partition coefficients, disequilibrium in either dataset, differences in monazite chemistry or the presence or absence of a third phase that competed for the available REE during growth. We urge caution against using empirically-derived partition coefficients from natural samples as evidence for, or against, equilibrium of REE-bearing phases until monaziteâgarnet partitioning behaviour is better constrained
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Pedagogical advantages of 3D virtual field trips and the challenges for their adoption
In a six-month long Innovate UK-funded project (November 2015 â April 2016), we investigated the feasibility of creating a sustainable national 3D âvirtual field-tripsâ (VFT) software service, to support and deliver field trip-based education through a virtual channel in schools and higher education institutions (HEIs). The idea of a 3D VFT service emerged from Virtual Skiddaw App, the 3D virtual geology fieldtrip, of The Open Universityâs (OU) Open Science Laboratory . In the feasibility project, we (at the OU) (co-investigator) along with Daden (project-lead) and Design Thinkers, UK (co-investigator) we looked into the technical, pedagogical, commercial and service design aspects of the 3D VFT service.
In this presentation, we focussed on the pedagogy strand of this feasibility project: pedagogical advantages of 3D VFTs, and the challenges for their adoption in schools and HEIs.
We discussed the following:
pedagogical underpinnings of 3D virtual environments and 3D VFTs in disciplines such as geology, biology, environmental science/studies and geography which are founded on field observations, exploration and enquiry;
potential of integrating VFTs within the curricula in schools and in HEIs;
perceptions of educators, students and assessment bodies towards 3D VFTs, and virtual fieldwork, in general; we used the Virtual Skiddaw App in workshops and presentations to illustrate the concept of a 3D VFT;
views of stakeholders towards the 3D VFT service: advantages, challenges and their requirements from this service.
Our empirical investigations have been user-centred â focussing on the stakeholders and particularly, the end-users such as educators, students and fieldwork specialists, and we have interacted with them via interviews, service design workshops, demonstrations and a survey to elicit their perceptions and requirements
Debris-flow release processes investigated through the analysis of multi-temporal LiDAR datasets in north-western Iceland
Debris flows are fastâmoving gravity flows of poorly sorted rock and soil, mixed and saturated with water. Debrisâflow initiation has been studied using empirical and experimental modelling, but the geomorphic changes, indicative of different triggering processes, are difficult to constrain with field observations only. We identify signatures to distinguish two different debrisâflow release styles by integrating highâresolution multiâtemporal remote sensing datasets and morphometric analysis. We analyse debris flows sourced above the town of ĂsafjörĂ°ur (Iceland). Two debrisâflow triggering processes were previously hypothesized for this site: (i) slope failure, characterised by landslides evolving into debris flows, and (ii) the fireâhose effect, in which debris accumulated in preâexisting, steepâsided bedrock passages is transported by a surge of water. It is unknown which process dominates and determines the local risk. To investigate this question, we compare airborne LiDAR elevation models and aerial photographs collected in 2007 with similar data from 2013. We find that two new debrisâflow tracks were created by slope failures. These are characterised by steep sliding surfaces and lateral leveed channels. Slope failure also occurred in two large, recently active tracks, creating the preparatory conditions for the fireâhose effect to mobilise existing debris. These tracks show alternating zones of fill and scour along their length, and debris stored below the sourceâarea at rest angles >35°. Our approach allows us to identify and quantify the morphological changes produced by slope failure release process, which generated the preparatory conditions for the fireâhose effect. As debris flows are rarely observed in action and morphological changes induced by them are difficult to detect and monitor, the same approach could be applied to other landscapes to understand debrisâflow initiation in absence of other monitoring information, and can improve the identification of zones at risk in inhabited areas near hillslopes with potential for debris flows
Molards as an indicator of permafrost degradation and landslide processes
Molards have been defined in the past as conical mounds of debris that can form part of a landslide's deposits. We present the first conclusive evidence that molards in permafrost terrains are cones of loose debris that result from thawing of frozen blocks of ice-rich sediments mobilised by a landslide, and hence propose a rigorous definition of this landform in permafrost environments. We show that molards can be used as an indicator of permafrost degradation, and that their morphometry and spatial distribution give valuable insights into landslide dynamics in permafrost environments. We demonstrate that molards are readily recognisable not only in the field, but also in remote sensing data; surveys of historic aerial imagery allow the recognition of relict molards, which can be used as an indicator of current and past permafrost conditions. The triggering of landslides as a result of permafrost degradation will arguably occur more often as global atmospheric temperatures increase, so molards should be added to our armoury for tracking climate change, as well as helping us to understand landslide-related hazards. Finally, we have also identified candidate molards on Mars, so molards can inform about landscape evolution on Earth and other planetary bodies
Debris-flow release processes investigated through the analysis of multi-temporal LiDAR datasets in north-western Iceland
Debris flows are fast-moving gravity flows of poorly sorted rock and soil, mixed and
saturated with water. Debris-flow initiation has been studied using empirical and
experimental modelling, but the geomorphic changes, indicative of different triggering
processes, are difficult to constrain with field observations only. We identify signatures to distinguish two different debris-flow release styles by integrating high-resolution multi temporal remote sensing datasets and morphometric analysis. We analyse debris flows sourced above the town of ĂsafjörĂ°ur (Iceland). Two debris-flow triggering processes were previously hypothesized for this site: (i) slope failure, characterised by landslides evolving into debris flows, and (ii) the fire-hose effect, in which debris accumulated in pre-existing, steep-sided bedrock passages is transported by a surge of water. It is unknown which process dominates and determines the local risk. To investigate this question, we compare
airborne LiDAR elevation models and aerial photographs collected in 2007 with similar
data from 2013. We find that two new debris-flow tracks were created by slope failures.
These are characterised by steep sliding surfaces and lateral leveed channels. Slope
failure also occurred in two large, recently active tracks, creating the preparatory
conditions for the fire-hose effect to mobilise existing debris. These tracks show alternating zones of fill and scour along their length, and debris stored below the source-area at rest angles >35°. Our approach allows us to identify and quantify the morphological changes produced by slope failure release process, which generated the preparatory conditions for the fire-hose effect. As debris flows are rarely observed in action and morphological changes induced by them are difficult to detect and monitor, the same approach could be applied to other landscapes to understand debris-flow initiation in absence of other monitoring information, and can improve the identification of zones at risk in inhabited
areas near hillslopes with potential for debris flows
Debris-flow release processes investigated through the analysis of multi-temporal LiDAR datasets in north-western Iceland
Publisher's version (Ăștgefin grein)Debris flows are fast-moving gravity flows of poorly sorted rock and soil, mixed and saturated with water. Debris-flow initiation has been studied using empirical and experimental modelling, but the geomorphic changes, indicative of different triggering processes, are difficult to constrain with field observations only. We identify signatures to distinguish two different debris-flow release styles by integrating high-resolution multi-temporal remote sensing datasets and morphometric analysis. We analyse debris flows sourced above the town of ĂsafjörĂ°ur (Iceland). Two debris-flow triggering processes were previously hypothesised for this site: (i) slope failure, characterised by landslides evolving into debris flows; and (ii) the fire-hose effect, in which debris accumulated in pre-existing, steep-sided bedrock passages is transported by a surge of water. It is unknown which process dominates and determines the local risk. To investigate this question, we compare airborne LiDAR elevation models and aerial photographs collected in 2007 with similar data from 2013. We find that two new debris-flow tracks were created by slope failures. These are characterised by steep sliding surfaces and lateral leveed channels. Slope failure also occurred in two large, recently active tracks, creating the preparatory conditions for the fire-hose effect to mobilise existing debris. These tracks show alternating zones of fill and scour along their length, and debris stored below the source-area at rest angles >35°. Our approach allows us to identify and quantify the morphological changes produced by slope failure release process, which generated the preparatory conditions for the fire-hose effect. As debris flows are rarely observed in action and morphological changes induced by them are difficult to detect and monitor, the same approach could be applied to other landscapes to understand debris-flow initiation in the absence of other monitoring information, and can improve the identification of zones at risk in inhabited areas near hillslopes with potential for debris flows.This work would not have been possible without a postgraduate studentship grant (NE/L002493/1) from the CENTA Doctoral Training Partnership funded by the UK Natural Environment Research Council (NERC) and the British Geological Survey University Funding Initiative Studentship (GA/14S/024, Ref: 284). We thank the NERC Airborne Research Facility Data Analysis Node for obtaining the aerial photography and LiDAR data, for the airborne survey project NERC ARSF 07217a in 2007 and for the airborne survey project NERC ARSF IG13â11 in 2013. We thank the NERC Geophysical Equipment Facility for technical support and for the loan number 1001. We would like to show our gratitude to JĂłn Kristinn Helgason (Icelandic Meteorological Office), who provided expertise that greatly improved the manuscript. We acknowledge constructive comments and suggestions from two anonymous reviewers. C. Jordan publishes with permission from the Executive Director of the British Geological Survey.Peer Reviewe