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Recent ARSF-supported Science: 2007

2007 Normal UK flying

2007 Overseas campaigns

GB07/01 Geraint Vaughan: Entraining Interfacial Layers in the Daytime Convective and Nocturnal Stratocumulus Capped Boundary Layer

Atmospheric turbulence is a topic of theoretical and practical importance. Turbulence transports heat and moisture from the Earth's surface to the atmosphere, and mixes air masses of very different origin in the free atmosphere. It is of importance to aviation, where severe turbulence can cause air accidents. Weather forecasters are continually searching for better ways to forecast turbulence. The first step to improving forecasts is to improve measurements of turbulence and to develop quantitative methods for remotely sensing it. Quantitative measurements are currently only available from in-situ platforms during dedicated measurement campaigns. The availability of routine, remotely-sensed turbulence measurements would be of benefit to a wide range of research and operational weather communities. Turbulence descriptions in nocturnal Sc capped boundary layers also require improvement to assist in pollution dispersion. We propose to exploit the known sensitivity of new radar wind profilers to atmospheric turbulence for this purpose. To date there have been very few studies which provide a method to do this. The project described here is a collaboration between Manchester and the Met Office and will combine ground based radar facilities with in situ balloon and aircraft turbulence measurements to address this problem.

GB07/02 Thomas Spencer: Extended monitoring of shoreline dynamics and ecosystem change following managed re-alignment

The artificial breaching of existing seawalls – 'managed realignment' - has been implemented to counteract habitat losses by re-creating saltmarsh on formerly reclaimed land. Changes in shoreline position and the re-establishment of tidal exchange are likely to have implications for salt marshes and mudflats in front of, and adjacent to, such newly created intertidal areas. However, the way in which such schemes should be designed for maximum benefit but minimal environmental impact on adjacent coastal ecosystems is still poorly known. Optical remote sensing, and particularly the recording of multi-spectral imagery from aircraft-mounted instruments flown over the coastal zone, offers a rapid, repeatable, non-intrusive and relatively large scale monitoring system for assessing these external impacts. The Wash Banks Flood Defence Scheme is being studied with ATM imagery collected once before breaching (pre- 9/2002) and three times thereafter, nested within a longer timeline (1970 – 2006) using aerial photography. This approach has identified the impact of inundation on formerly reclaimed land, the relative stability of the existing saltmarsh surface and the major changes to the depth and distribution of creeks. It is crucial that this data collection is continued to demonstrate the full impacts over a realistic time interval.

GB07/03 John Scullion: Modelling soil hydrology and biodiversity as affected by microtopography

LiDAR and CASI will be flown over Rhos pasture communities, sites of species-rich semi-natural wet grassland with complex soil hydrology and microtopography features. The flight data will be reconciled with detailed ground-based soil and vegetation surveys in order to model the hydrological regimes in effect.

Microtopography is intricately linked to soil development and moisture regime, and these factors influence vegetation community development. Variation in soil moisture across small spatial areas can produce sharp community transitions and encourage biodiversity.

The overall aim of the research is to develop a system for modelling the hydrology and vegetation community development at these sites, predicting areas of high diversity or those presenting suitable conditions for the re-establishment of particular communities. The work has potential applications in habitat conservation and restoration.

GB07/04 Peter Halkon: Hayton Remote Sensing project

The Hayton Remote Sensing project intends to collect lidar and CASI/ATM data to contribute to a growing body of work developing the methodology for the use of lidar for archaeological landscape studies detection contextualize and to expand more than 10 years of intensive study of the archaeological landscape around Hayton, East Yorkshire. Because of the long history of archaeological study around Hayton, it provides ideal ground for methodological testing. Close comparison between extant survey and excavation data, geophysical survey, detailed soil maps, and historical aerial photography will permit detailed analysis of the success of lidar survey in identifying buried and surface archaeology. The lidar data provides micromorphological detail that assists in the interpretation of field survey results by providing explanations for archaeological visibility based on patterns of landscape degradation. It also provides a means of accurate planning of a complex of sites within the Hayton area and in the countryside beyond. The collection of CASI/ATM data will allow the detection of soilmark type sites and the comparison between sites detectable through spectral and elevation variations.

GB07/05 Andrew Tyler: Strategies to manage toxic cyanobacterial blooms in lakes: remote sensing, modelling and cost benefit analysis

Cyanobacteria are natural inhabitants of freshwaters, where they fulfil key roles in the cycling of matter and the biodiversity of aquatic communities. They present both short- and long-term hazards to the health of humans and other animals especially when growing as mass populations (blooms, scums, biofilms) primarily because they produce numerous potent toxins.
Progress has been made on aspects of toxic cyanobacterial risk management through:

  1. toxicity assessment of microcystins;
  2. application of effective modelling methods to hindcast bloom histories and forecast bloom events;
  3. development of national risk assessment schemes for lakes;
  4. development of sensitive, robust specific physicochemical and antibody-based methods for cyanotoxin analysis.

However, substantial gaps remain. Cyanotoxin detection and analysis methods generally need a high level of technical skill, specialised equipment, are costly and do not provide synoptic indications of toxin distribution. Similarly, identification of cyanobacteria is costly, prone to observer error and often inaccurate.

To permit a proactive, rather than reactive, strategy development for health protection, systems are needed to provide early warnings of potentially toxic cyanobacterial blooms, so here we propose to develop and evaluate a synoptic approach to providing early warning of toxic cyanobacterial development for the protection of animal and human health.

GB07/06 Doreen Boyd: Level 1 Validation of the Envisat MERIS Terrestrial Chlorophyll Index (MTCI)

Satellite remote sensing provides the opportunity to measure and monitor key photosynthetic pigments such as chlorophyll content of vegetation canopies, which are a key and dynamic component of global ecosystems. The widely accepted red-edge algorithm, used to estimate chlorophyll content from remotely sensed data, is not suitable for use with satellite imagery. To overcome this problem, the new Envisat MERIS Terrestrial Chlorophyll index (MCTI) has been developed. It is the only satellite chlorophyll index available for use and is available to users as a Level 2 product from the European Space Agency. However, there is a need to validate the MCTI. Data provided as part of a NERC ARSF campaign is a key part of the validation procedure; this research proposes that the MCTI be validated via high resolution imagery (CASI) and LiDAR point cloud data. The validation sites in Dorchester and the New Forest with its vegetation types provide a range of chlorophyll contents to be studied. Validation results will be useful to the producers (ESA) and users of the MCTI products and to refine further validation efforts.

GB07/07 Tim Malthus: Hyperspectral and Phenological Characterisation of Upland Heather Dominated Ecological Communities

Heather dominated uplands form a significant proportion of Scotland's land area, are of international importance for biodiversity conservation, are a hydrological buffer and are intimately linked to the global carbon cycle. Current management practices are considered to be causing the decline of these areas and climate change may be contributing. The extent and remoteness of upland moors makes manual survey problematic for monitoring ecological and phenological change. Remote sensing offers a complimentary approach. However, little is known of the detailed reflectance properties of heather or the influence of variations in key biophysical and biochemical parameters on the spectral reflectance of heather canopies.

Laboratory and field measurements of hyperspectral reflectance and the biophysical and biochemical variables influencing reflectance have been acquired from a range of heather age classes and ecological communities throughout the 2005 and 2006 growing seasons from an upland site on the west coast of Scotland. Airborne hyperspectral RS and aerial photographic surveys are now proposed with concurrent canopy reflectance studies and atmospheric and biophysical field measurement being taken. Reflectance modelling methods and Object-Oriented image analysis will be used to increase understanding and detailed classification of these heather dominated ecological communities.

GB07/08 Graham Ferrier: A new, robust approach to modelling methane (CH4) emissions from northern peatlands.

Northern peatlands are the most important class of peatland in terms of aerial extent and also the most important in terms of vulnerability to climate change. To understand the scale and effect of climate change on the northern peatlands requires a modelling based approach integrating peatland CH4 emissions models ith 3-D, process-based model of peatland micro- and macro-succession. The extreme heterogeneity and microtopography variability of peatlands means that to scale these models up from the plot (1m2) to the ecosystem (103-104 m2) and then to landscape scales (104-105 m2) requires accurate characterisation of the peatland structures and types at a very high spatial resolution. The objectives of this proposal are :

GB07/09 Martin Kirkbride: Quantification of supraglacial sediment flux using airborne LiDAR and ATM at alpine glaciers

Application is made for remote sensing support for research into the processes and rates of supraglacial debris cover formation on alpine glaciers, and on the response of glaciers to increases in supraglacial mass loading. At Glacier d'Estelette (45°;46'26"N 6°48'50"E), acquisition of LiDAR data will provide a DEM which will serve as a base map for ongoing field experiments, a source of derived topographic information to help to explain variations in mass load and transport rate, and as a datum surface against which changing ice volume and glacier extent can be measured since a 2004 dGPS survey and by planned future monitoring. ATM data will permit mapping of debris-covered area, again to provide a baseline survey for future comparison and to calculate current mass load. At Brenva Glacier (45°49'00"N 6°55'35"E), a LiDAR-derived DEM will allow comparison of 1997-2007 ice volume changes following a major (6 x 106m3) rock avalanche. Such catastrophic processes of mass loading have become more frequent in the last decade as mountain permafrost has degraded, leading to an enhanced risk to human life and infrastructure. On the other hand, the thermal insulation provided by rock avalanche deposits may offset, in the short-term, glaciological response to warming climate.

GB07/10 Benjamin Brock: Remote sensing of thermal properties and climate change response of debris-covered glaciers.

Debris-covered glaciers are becoming increasingly common in the world's mountain ranges due to climatic warming, but the insulation and reduction in ablation provided by debris covers has not been accounted for in projections of glacier retreat and downstream runoff under climatic warming scenarios (e.g. Stern, 2006). The proposal is to develop and test airborne remote sensing techniques for the measurement of the key thermal properties of glacier debris covers required in numerical melt modelling of buried ice, in order to assess applicability of the methodology to suitable satellite sensors, e.g. ASTER. Specifically, we will:
i) map variations in debris emissivity across a debris covered glacier using CASI data combined with field thermal infrared spectroradiometer measurements, in order to assess its impact on remote-sensing derived maps of debris surface temperature and thermal resistance and
ii) assess the significance of high spatial variability in debris surface properties affecting temperature and thermal resistance at the 90 m ASTER pixel size using ATM and ground based measurements. Finally, airborne LiDAR will be used to measure and assess recently observed rapid ice thinning beneath debris-covers at the target site, where a series of DEMs going back to 1913 are available.

GB07/11 Duncan Irving: The characterisation of the lithologies, structures and superficial deposits of the Torridonian mountains in an integrated digital outcrop study.

The mountains of Torridon are the setting for two digital outcrop studies using a terrestrial LiDAR. A regional study of extensive sections of deltaic sediments provides insight into the processes that form a large depositional system. The walls and deposits of two coires on the north side of Beinn Eighe are key localities in understanding the nascent flickering of the Gulf Stream at the end of the last ice age. Accurate digital mapping is the key to developing better models to understand both the processes that created the rocks, and those that caused the last ice age to leave the overlying deposits.

In both projects, the use of airborne LiDAR and digital photography will provide a bridging dataset between localised terrestrial LiDAR data, and regional DEMs. Spectral and thermal classification of the rocks and superficial deposits will generate maps which will precisely locate glacier fronts that can be dated to create a regional chronology of the last phase of the last ice age, and provide compositional information that will allow the seed points to be linked across terrain inaccessible to the human mapper.

Finally, Torridon is a "classic" area of British geology and a publicly-available teaching resource will be developed.

GB07/12 Andrew Wilson: Spectral analysis of UK peatland fires via airborne remote sensing: detection of 'flaming' k-emission lines and mapping of plume trace gases

Biomass burning worldwide releases significant amounts of terrestrially-stored carbon to the atmosphere, in the form of carbon dioxide, carbon monoxide and methane gases. Many of the products are greenhouse species, and with the accompanying smoke aerosols can affect the local energy balance and climate globally. The UK has 10-15% of the worldwide habitat of heather peatland and prescribed fires (for the clearance of heather and the support of grouse populations) and accidental fires have been shown to have major impacts on both the ecology and carbon balance of these areas. High intensity (flaming) fires produce predominantly carbon dioxide, whilst low intensity (smouldering) fires produce a wider range of products with more carbon monoxide, methane and other complex hydrocarbons. Whilst it is the overlying heather that is ignited during such fires, it is anticipated that the underlying carbon-rich peat also burns to some extent. We intend to integrate a range of remote sensing techniques to monitor the proportions of the high and low intensity fires and try to quantify the amount of pyrogenic carbon conversion for a) a low energy prescribed peatland heather burn (Feb-March), b) an opportunistic higher energy accidental fire that commonly occurs during the summer (June-August). The results could have a major impact on understanding the effect of such burning on this important UK peatland habitat, which represents 90% of total terrestrial UK carbon reserves.

GB07/13 Genevieve Patenaude: Remote sensing for the integrated management of Loch Lommond and the Trossachs community forest

This project aims at developing an effective and integrated forest management and monitoring approach for community forest stakeholders, which include local land owners, communities, authorities and forest managers, as they are required to make coherent, informed decisions regarding forest resources and their future. In this context, the project will make use of local knowledge, GIS and remote sensing technology to inform decision making.
The following questions will be addressed:

Recent introduction of sustainable continuous cover forestry (CCF) is leading UK forest management away from traditional, single age, monoculture clear felling to that of a more 'natural' forest, composed of multiple species, ages, diameters and heights. The park has been designated to be trialled for CCF.

This new management approach raises several challenges as different stakeholders will require information about the current state of the park, and subsequent changes to these areas, the kind of products to be extracted in the future and ways to monitor the whole process.

IPY07/01 Jonathan Carrivick: Quantitative modelling of a volcanically-influenced proglacial system

The overall aim of this project is to undertake an interdisciplinary study of glacial meltwater discharge, proglacial floodplain dynamics, and ecological response in a volcanically-influenced proglacial river system. Whilst these three components have been studied separately in detail, quantification of their interactions has so far not been attempted. This research gap is important due to the requirement for accurate prediction of 1) Climate change effects on proglacial systems, 2) Volcanic / geothermal effects on proglacial systems, and 3) the effect of each of the above on river biodiversity. These effects will be addressed by: (1) Modelling meltwater production on Kverkjökull, Iceland (2) Modelling river discharge and sediment mobility of the Volga-Skolpa outwash fan in response to (1), and (3) Modelling spatial and temporal stream macroinvertebrate community response to (1) and (2). To achieve these aims field measurements will be made of; (i) Kverkjökull surface topography (LiDAR) and snow-ice interface, (ii) Collection of meteorological data (iii) Volga-Skolpa outwash fan surface topography (LiDAR), (iv) River bed substrate and hydraulics, and stream macroinvertebrate communities. Field measurements will inform development, validation and integration of a (a) Distributed energy balance model (Arrell et al., in press), (b) Fluvial landscape evolution/stability model (e.g. Carrivick, 2006), and (c) A model of ecological response to meltwater dynamics (Brown et al., 2003).

IPY07/02 Neil Mitchell: Lava penetrating water: Nesjahraun, Thingvallavatn, Iceland

We request LiDAR data to record the surface morphology of lava that entered a lake on Iceland 2,000 years ago. Surface relief and flow-wise gradients will be quantified from these data to compare with similar measurements from geophysical data collected within the lake in 1997 and previously. On entering water, lava becomes effectively less dense because of buoyancy and cools more rapidly because of water's greater heat capacity than air. Volcanic islands, where water-entering flows have been located previously, are typically strongly eroded by sea-swell around coasts so they usually provide poor information on morphological effects of buoyancy and cooling in shallow regions, but lavas emplaced into lakes are less affected. This target Thingvallavatn lava indeed shows evidence for an abrupt steepening 0-20 m below water level that could be caused by inflation of the lava as it lost effective density immediately on entering water. Combined with further fieldwork and analysis of sample physical properties, this project therefore seeks to address the behaviour of lava in a site only 30 km from Reykjavik.

IPY07/03 Richard Hodgkins: Contemporary spatial and temporal patterns of sediment supply, availability and transport in proglacial aeolian systems.

Across the continents there is a clear association between the distribution of wind-blown sediments and the former extent of ice sheets and glaciers. Glacial erosion processes produce significant quantities of fine sediments that are washed out from beneath glaciers by meltwater. If these sediments are deposited on the glacier's floodplain and dry out, then the wind may entrain and transport them across the landscape resulting in the formation of sand dunes and loess, and also adding very fine particles (dust) to the atmosphere. The overall objective of this research is to improve our understanding of the relationship between glacially-driven fluvial and aeolian processes in proglacial areas, particular in terms of sediment budget. The methodology is based on monitoring fluvial sediment fluxes at proximal and distal ends of a well-constrained proglacial valley in Greenland, and monitoring aeolian fluxes at multiple cross-sections within the valley. The outcome will be a comprehensive sediment budget, including an assessment of the contribution of glacifluvial material to the aeolian system. Airborne remotely-sensed data will support the research through generating a Digital Elevation Model for (1) terrain analysis to quantify stable and vulnerable land units; (2) nested-scale surface roughness measurements.

IPY07/04 John Murray: Investigation into the Processes Controlling Debris Flows in the Westfjords Region, Iceland. (PhD: Recent Water Flows on Mars: a laboratory, field and image based approach.)

Using the LiDAR instrument it is proposed that high resolution topographic data are collected on gullies on slopes in the Westfjords region of Iceland. This will allow for detailed comparison to be made between gullies in Iceland and those of a similar scale on Mars. The data collected from the LiDAR instrument will be of a similar resolution to the best topographic data for Mars. The resulting high resolution data will assist in the determination of the active geological processes. The topographic dataset cannot be collected by ground surveying, as the slopes in this area are too hazardous, so this survey presents a unique opportunity study terrestrial debris flow gullies. The project will contribute not only to the debate over the existence of water on the present-day Martian surface, but also to the analysis of risk posed by debris flows to the Westfjords inhabitants.

IPY07/06 Adrian Luckman: Ice dynamics, calving and recession at Breiðamerkurjökull, Iceland

The process of calving at glaciers terminating in water accounts for a significant part of the flux of ice from the cryosphere to the oceans, and appears to be increasing as a result of climate change. There is an urgent need to better understand the mechanisms behind ice fracture, crevasse opening and calving events, so that the effects of climate change on the cryosphere can be better predicted. Breiðamerkurjökull makes an excellent case study for such theoretical development and provides a community test site for a range of ice-dynamic and geomorphological investigations. This project will directly address these topics by acquiring and analysing an unprecedented dataset for dynamic and volumetric analysis. In choosing Breiðamerkurjökull, a lake-calving glacier, a large body of associated data becomes available including a bed DEM and historical topographic data. The ARSF AOI offers a unique chance to gain repeat lidar and aerial photograph datasets which are unlikely to become available by other means. The research team brings together a wide range of scientists to develop this community test site, and includes experts in data processing and geophysics (Swansea), topographic change and geomorphology (Evans and Twigg), calving processes (Benn and Mottram) and glacier modelling (Aðalgeirsdóttir and Bjornsson).

IPY07/07 David Graham: Glacier response to a changing climate in southern Iceland

Three inter-related themes will provide new baseline datasets for the rigorous evaluation of the timing and mechanisms of glacial response to climatic forcing at a range of contemporary ice masses. Global warming is predicted to have a pronounced effect on terrestrial ice masses but predictions of how ice masses will respond to future warming depend on rigorous understanding of the relationship between climatic change and recent glacier activity. The mass balance of glaciers in southern Iceland is closely coupled to North Atlantic Ocean circulation and these glaciers are therefore highly sensitive barometers of regional climatic change. Consequently, proglacial landforms in southern Iceland are archives of North Atlantic climate change and provide an important resource for the evaluation of both the timing and mechanisms of ice mass response to recent climatic forcing. Proglacial areas in southern Iceland have been subject to regular aerial survey since the 1940s providing important insights into both the timing and mechanisms of glacial retreat. However, since the Icelandic mapping agency ceased routine aerial photography, this fundamental avenue of research has been curtailed.

IPY07/08 Ian Willis: Mass Balance Modelling of Langjökull, Iceland

Langjökull, Iceland's second largest icecap, is losing mass over twice as fast as the larger Vatnajökull. The main aim of this proposal is to use 10m LiDAR and ATM data to develop a physical mass balance model to predict Langjökull's response to climate change and its contribution to sea level. The DEM will provide the topographic control on the model. The ATM reflectance data will be used, with satellite and in situ measurements, to parameterise spatiotemporal albedo variations. The model will be driven by GCM output, ERA-40 reanalysis, surface weather records and statistical downscaling, and will be tested against point mass balance measurements collected since 1996. It will also be compared with volume changes derived by comparing the LiDAR DEM with earlier, coarser photogrammetric DEMs for the entire ice cap and for one of its outlet glaciers. Our second aim is to investigate the effects of DEM resolution on net shortwave radiation receipt and melting, using 2m LiDAR data collected over two outlet glaciers. The third aim is to use 2m LiDAR data to quantify the characteristics of glacial geomorphological features (e.g. size, shape, distribution of lineations, drumlins, flutes, moraines, eskers), to elucidate subglacial processes beneath these surge type glaciers.

IPY07/09 Tim Wright: The relationship between faulting and magmatism in the Krafla rift segment, Iceland.

Iceland sits on the Mid-Atlantic Ridge (MAR) – the boundary between the American and Eurasian plates, which are moving slowly apart at 2 cm/yr, the speed your fingernails grow. Although the motion of the two plates is steady in the plate interiors, it is highly episodic in the plate boundary zones. The Krafla segment of the plate boundary is 80 km long, and was highly active from 1975 to 1984 – when the two plates moved apart by up to 9 metres in places, and a series of dramatic volcanic eruptions (the Krafla fires; Figure 1) changed the landscape [e.g. Tryggvason, 1984; Sigmundsson, 2006]. We propose to acquire new high-resolution data sets over Krafla to investigate the relationship between the surface topography, cut by many faults and fissures, the magma that was erupted at the surface, and the larger volume of magma that was intruded below the surface. This will complement other knowledge about Krafla, allowing detailed insights into the link between faulting and magmatism. The work in Krafla will have direct relevance for our funded work in Afar, Ethiopia, where a similar sequence of events began in September 2005, and where the NERC ARSF will acquire data in January 2008. The two data sets will help us determine how tectonic plates move apart and new crust grows.

IPY07/10 Andrew Shepherd: An investigation of the link between accelerated ice discharge and surface melting at the Greenland Ice Sheet

This proposal is to record airborne LiDAR and camera observations to investigate the extent to which the processes of accelerated glacier discharge [e.g. (Rignot and Kanagaratnam, 2006)] and increased surface melting [e.g. (Box et al., 2006)] at the Greenland Ice Sheet are linked. Specifically, we propose (i) a survey of supra-glacial lake geometry to constrain a model of lake evolution and discharge, and (ii) a survey of glacier discharge downstream of supra-glacial lakes to determine the extent to which both land- and marine-terminating glaciers have experienced secular and seasonal velocity fluctuations. Together, these experiments will provide data sufficient to assess the current and future stability of the Greenland Ice Sheet to projected (Church and Gregory, 2001) climate warming.

IPY07/11 Tavi Murray: Thinning of south-eastern Greenland outlet glaciers

The Greenland Ice Sheet's contribution to sea level rise has more than doubled in the last decade (Rignot & Kanagaratnam, 2006). This dramatic increase has resulted from the acceleration, thinning and marginal retreat of a few major outlet glaciers, mainly in the south-east (Luthcke et al., 2006). These changes have profound implications for global sea level, ocean circulation and regional climate, but we do not fully understand how long the thinning has been ongoing, whether its rate is unprecedented, or what the controlling processes are. This project aims to extend to 60 years the temporal length of the record of thickness changes over two major South Eastern Greenland glaciers. We will also produce detailed surface DEMs to estimate changes in ice volume and ice velocities suitable for use in glacier modelling. This project forms part of approved IPY cluster MARGINS (Co-ordinators Fahnestock & Murray).

IPY07/12 Meredith Williams: An evaluation of VIS-SWIR reflectance correction approaches for high latitude glaciated environments, Skeiðarárjökull & Skeiðarársandur, SE Iceland

Cost and time-effective reflectance correction is an important issue for multispectral and hyperspectral imagery from both airborne and spaceborne platforms. In high latitude glaciated environments data acquisition conditions often fall outside the range of illumination levels and solar elevations considered acceptable for mid latitude deployments. System performance can also be compromised by the wide range of target brightness levels encountered around glacial margins. This project will directly compare the performance and appropriateness of a range of simple VIS-SWIR reflectance correction procedures for airborne sensors such as CASI-2, ATM, Eagle and Hawk under varying conditions, utilising a small test site that falls within the well established and resourced EarthWatch Institute long-term monitoring project site in Skaftafell, SE Iceland. The approaches adopted will include radiative transfer modelling from FSF sunphotometer derived parameters and a variety of empirical line based methodologies using a range of ground calibration targets. The results will be directly compared with those achieved with ARSF imagery acquired during the 2006 NCAVEO Chilbolton experiment and the HY05/03 ARSF deployment. The final results will be used to provide recommendations on the optimal choice of reflectance correction methodologies for future airborne remote sensing campaigns in high latitude glaciated environments.

IPY07/13 Andrew Russell : Characterisation of ice-marginal landscape change and proglacial fluvial response to rapid glacier retreat, Skeiðarárjökull, Iceland using airborne LiDAR

Although glacier retreat is occurring at many locations worldwide, there is a notable lack of data concerning the coupling of glacial and fluvial processes in driving geomorphological change and sediment transfer during periods of ice recession. Our understanding of the relationship between glacier fluctuations and changes in the glacial and proglacial fluvial system is derived predominantly from the study of relatively small alpine glaciers or from interpretation of the landform and sedimentary record. Skeiðarárjökull is a large surge-type glacier which is subject to high magnitude glacier outburst floods (jökulhlaups). The 23 km wide frontal ice lobe feeds the world's largest active outwash plain (1000 km2). Due to its scale and complexity the Skeiðarárjökull glacial system is considered a suitable analogue for lower latitude Quaternary ice-masses. This project aims to characterise the rapidly evolving ice-marginal landscape of Skeiðarárjökull, Iceland. Acquisition of LiDAR-derived DEMs and aerial photo coverage of the ice-marginal zone of Skeiðarárjökull will provide an essential benchmark data set, enabling rates of elevation change, landform development and sediment transfer to be quantified. Fieldwork-derived sedimentary data collected annually since 1996 at Skeiðarárjökull will allow better understanding of (1) the response of fluvial system to glacier retreat and (2) the role of glacier surges and jökulhlaups in creating distinctive landforms. This project will provide a vital data set which can be used for hydraulic modelling of jökulhlaups allowing prediction of future flood paths and impacts.

ET07/01 – Consortium grant, see ET07/04

ET07/02 William Murphy: Correlating terrain systems and representative values – putting geotechnical numbers into geomorphological images.

Landslides constitute a significant hazard to road engineering in developing environments. In such case it often proves prohibitively expensive to deploy extensive ground investigation over large areas. Furthermore, the high likelihood of significant damage to communication networks in mountain areas often makes significant investigation of lifelines difficult to justify. In recent years extensive work has been carried out to develop geomorphological methods to support low cost road engineering. However, in many cases it is still essential to deploy engineering geologists on the ground in areas that may be dangerous. This proposal outlines a request for data in Central Ethiopia which is currently the object of an Ethiopian Roads Authority upgrade. The geomorphological survey work has been carried out by Scott Wilson as consultants with rock mass data currently being collected under the supervision of Drs Hearn (Scott Wilson) and Murphy (University of Leeds). The aim is to develop a methodology by which airborne remote sensing data can be used to provide quantitative measures of rock mass properties based on limited ground truth. The methodology outlined will find application in areas beyond Ethiopia in a variety of morphoclimatic environments.

ET07/03 Graham Ferrier: Mapping geothermal and epithermal deposits in the Ethiopian Rift Valley

The Main Ethiopian Rift (MER) is in an advanced stage of evolution associated with modified crust and is an ideal study area for improving understanding of continental break-ups. The MER is associated with bimodal Quaternary magmatism. Field and geochronology data have been used to examine the relationships between acidic volcanoes and basaltic eruptions. The overall aim of this project is to characterise the interaction between the different types (and ages) of magmatism, the different types and distributions of faulting and the distribution of geothermal and epithermal systems in order to gain a better understanding of the tecto-magmatic processes occurring at a continental rift setting. The objectives of this project are : • integrate LiDAR-derived DEMs with geological maps derived from processing of hyperspectral/ATM remote sensing datasets to resolve the spatial patterns and interrelationships between the different phases and types of magmatic activity and faulting • differentiate the diagnostic minerals representing the hydrothermal alteration zones associated with the geothermal and epithermal deposits • integrate the results with Hyperion and ASTER imagery to investigate tecto-magmatic processes and identify locations of geothermal and epithermal systems in other parts of the rift valley

ET07/04 Tim Wright: The Hararo Rift Segment in the Afar Triple Junction, and geohazards in the Afar capital, Semara.

The Afar region in Northern Ethiopia sits on a tectonic triple junction above a hot spot in the Earth's mantle, where the Arabian, Nubian (African) and Somalian plates pull apart. The plate boundary zones are segmented into ~60-km-long rift segments, similar to those seen at mid-ocean ridges. Such structures are usually inaccessible to remote sensing techniques as they are covered by 2.5 km of water. In September 2005, the Dabbahu rift segment, on the Arabia-Nubia boundary, underwent a major rifting episode – 2.5 km3 of magma was injected into a volcanic dyke along the entire segment, which pushed the plates apart by up to 8 metres. The Hararo rift segment lies immediately to the south of the Dabbahu segment and is geologically and structurally very similar. We propose a survey that will characterise the style of previous volcanic and tectonic events on the Hararo segment, which has no historic record of activity. These data will be compared to similar data sets from the Dabbahu segment (January 2008) and Krafla (Summer 2007) in Iceland. We will used the data sets to determine likelihood of a major rifting episode on the Hararo segment, on which the regional capital, Semara, is being constructed.

ET07/05 Graham Ferrier: Determining engineering parameters of expansive soils using an integrated airborne and field spectroscopy and geophysical dataset

Conventional methods of assessing the geotechnical properties of expansive soils are expensive, time consuming and provide only sparse point samples. The presence, nature and spatial distribution of these soils can be overlooked leading to inadequate surveying of construction sites, inappropriate design specifications and subsequently result in damage to life and property. There is therefore an urgent need to develop a methodology that can accurately map these soils types, over large areas at low cost. Reflectance spectroscopy has been demonstrated to have the capability to identify and quantify specific engineering parameters of expansive soils. As the geotechnical problems of expansive soils are not only lateral, three-dimensional subsurface information is required and the vertical variation in properties of expansive soils needs to be resolved to provide engineers with more information. The aim of this project is to develop empirical models for quantitative measurement of engineering parameters of expansive soils from spectral reflectance. Ground geophysical survey data will be integrated with the results of the remote sensing study to develop a generalised 3D subsurface profile model to resolve the thickness and variability in properties of expansive soils. Integration of results from the airborne study would be used to calibrate measurements from satellite imagery.

ET07/06 Ian Willis: Land Use Patterns and Change in Konso, Ethiopia

Konso is a culturally important region of Ethiopia because of its indigenous and intensive agricultural practices, where the local people have integrated agro-forestry, terraces, and other soil and water conservation practices in order to cultivate food over many centuries. Population growth and possibly climate change in the region mean this traditional way of life is increasingly under threat with potentially disastrous consequences. Research, primarily in the social sciences, suggests that population and climate pressures are forcing people to migrate from the traditional highland areas to lowland areas where climate and soils are even more marginal for agriculture. There are, however, no data that can be used to quantify the patterns of settlement, natural vegetation, agricultural practices and soil / water conservation measures and their changes through time. Our proposed study will combine environmental and social science methodologies to investigate such patterns and changes. Concentrating on a 10x30km region of Konso, we will obtain airborne LiDAR data, hyperspectral reflectance data and vertical photographs in January 2008. Ground truthing will be used to classify the hyperspectral data, and the combined data sets will be used to generate digital maps of topography (and derivatives), land use (settlements, trees / shrub species, crop types, terracing, irrigation patterns), soil moisture and erosion. We will be able to investigate the relationships between these variables. Comparisons with geo-rectified historic air photographs together with the results of semi-structured interviews with local farmers will enable us to assess the extent of settlement and landuse changes over the last few decades and the extent to which they are sustainable.

ET07/07 Richard Bates: Late Pleistocene desiccation of Lake Tana, Source of the Blue Nile

The Blue Nile has its source at Lake Tana in northern Ethiopia, and flows 1610km to its confluence with the White Nile at Khartoum. Although shorter than the White Nile, it contributes ~56% of total Nile discharge, rising to 68% during maximum flow, and the bulk of transported sediment. However, much less is known about the Quaternary-Tertiary geological history of the Blue Nile and its headwaters than for Lake Victoria, the source of the White Nile. A recent NERC-funded research programme on Lake Tana has provided new core data (Lamb et al., 2007) that show Tana dried out at about 17,000 cal BP, contemporaneous with desiccation of Lake Victoria. The seismic data reveal a previously unknown, thick (+100 m) sedimentary sequence with basin-wide reflecting horizons strongly suggesting numerous earlier regional, and possibly global (Heinrich?), climatic events. This was an unexpected discovery and, in order to best interpret this record, a much more comprehensive knowledge of the surrounding geology and regional tectonics is required. Due to the size of the basin (ca. 70 x 100 km) and minimal road network, airborne mapping backed by judicious ground truthing will provide the only feasible solution to obtaining the required data.

ET07/08 Tim Wright: Mapping the Resources, Environment and Geohazards of the Ethoipian Capital, Addis Ababa

Addis Ababa is home to more than 3 million people, accounting for 25% of the urban population [Central Statistical Agency, 2006]. It is built on a western embayment of the Main Ethiopian Rift (MER), and the built-up terrain slopes southwards from about 3,000m a.s.l. on the Entoto hills to about 2,100 at Kaliti in the south. It is currently undergoing an unprecedented construction boom where many low-value, low-rise properties are being replaced by high-value, high-rise buildings. The rapid development of the city is causing a number of concerns: the natural supplies of water, geothermal energy, and building materials are limited but poorly mapped; the environment has been degraded by development; and a significant hazard due to earthquake potential exists. We propose an airborne campaign to acquire high resolution imagery and topographic data. We will use these data sets in conjunction with other geological and geophysical data to: 1. improve knowledge of local hydrology; 2. explore new sources of geothermal energy; 3. map the surface geology; 4. provide a baseline inventory of remaining forestry; 5. assess tectonic geohazards.