From 1 - 3 / 3
  • A geographic information system (GIS) heat flow and temperature model of East Africa created by extracting data from open sources into a series of shapefiles and rasters containing information on geothermal sites, hot spring locations, digital elevation model, surface temperature, geothermal gradients, thermal conductivities and heat flow data, major faults, surface geology, crustal basement, electrification grid system and population density across East Africa. This data is stored in the World Geodetic System (WGS) 1984 Geographic Projection System.

  • We present Curie depth point (CDP) and geothermal heat flow (GHF) estimations based on spectral analysis of magnetic airborne data for the Transantarctic Mountains (TAM) and Wilkes Subglacial Basin area. The Curie depth point is defined as the depth at which the Curie Temperature of 580 degC is reached. The Curie Temperature describes the temperature at which magnetic minerals lose their ability to generate a strong magnetic field. We use exclusively high resolution magnetic airborne measurements from the ADMAP-2 compilation, where we have removed data with a 15 km blanking distance threshold to reported flight lines to minimise artefact from interpolation. The obtained magnetic dataset is upward continued to a constant station height of 4 km and subdivided into window with a window size of 200 km, 300 km, and 400 km. For each window we calculate the power spectrum and estimate the CDP from the power spectrum. Subsequently we estimate the magnetic data coverage for each window and discard CDP estimates for window below a data coverage threshold of 80%. From the CDP interface GHF is forward calculated assuming constant thermal conductivity for the crust and a constant temperature at the base of the ice sheet representing the pressure melting point. This study is motivated by the need of high resolution GHF models form the Icesheet modelling community especially in marine based Basins like the Wilkes Subglacial Basin as well as by interpretation of the origin of the Transantarctic Mountains. Recent seismic studies have argued that warmer west Antarctic is present beneath the Transantarctic Mountains, which give thermal support to the mountains range. This hypothesis should lead to increased GHF in the area and therefore can be tested against our GHF model. Our results show elevated heat flow in the area of the Transantarctic mountains supporting the idea of thermal support for the mountain range with an independent method. Furthermore, we image elevate heat flow in the central Basin of the Wilks Subglacial Basin and Rennick Graben which have not been imaged before by continent wide GHF models. Funding for this research was provided by NERC through a SENSE CDT studentship (NE/T00939X/1)

  • Categories  

    The OSCAR (Oceanographic and Seismic Characterisation of heat dissipation and alteration by hydrothermal fluids at an Axial Ridge) data set is an interdisciplinary collection of physical oceanography and geophysics measurements. Data collection took place in the Panama Basin, bounded in the north-west by the Cocos Ridge, by the Carnegie Ridge in the south and by South and Central America in the east and north, respectively. Measurements were collected during RRS James Cook cruises JC112 and JC113 (05/12/2014 to 16/01/2015), RRS James Cook cruise JC114 (22/01/2015 to 08/03/2015) and RV Sonne cruise SO328 (06/02/2015 to 06/03/2015). The project investigated the effect of the cooling of young oceanic crust close to a mid-ocean ridge. It is here that rapid cooling is dominated by hydrothermal circulation of seawater through the crust, which is then discharged into the ocean along the ridge. Once in the ocean, released heated seawater mixes with the ambient cold water to form a plume, which provides a mechanism to lift the densest waters away from the bottom boundary layer. Data were collected using Bottom Pressure Recorder, Acoustic Doppler Current Profiler (ADCP), Magnetotelluric Lander, CTD, Vertical Microstructure Profiler, Synthetic Aperture Radar, Ocean-bottom seismograph and Multibeam echosounder. Measurement of salinity, oxygen and helium were also made and zooplankton samples collected with vertical net casts. This multidisciplinary, collaborative research project was led by Professor Richard Hobbs at the Department of Earth Science, University of Durham, UK and funded by Natural Environment Research Council (NERC) grant NE/I027010/1.