OzFuel Pre-Phase A Study

This document presents the results of a Pre-Phase A study for the OzFuel bushfire fuel monitoring mission in accordance with NASA system engineering standards. The OzFuel Pre-Phase A Study (Australian Forest Fuel Monitoring from Space) report was developed by the Australian National University (ANU) Institute for Space for Geoscience Australia (GA) and CSIRO in support of their contribution to Australia’s Satellite Cross-Calibration Radiometer (SCR) and AquaWatch missions (UNSW Canberra Space, 2021). The OzFuel study conceptualises a multispectral bushfire fuel monitoring satellite mission to fulfil two major goals: To launch a dedicated science and research mission to mitigate the risk of future catastrophic bushfires; and To deliver an Australian designed and built pathfinder mission to de-risk the SCR program. Key outcomes of the OzFuel mission are: Australian capability enables the forward-looking development of a fully operational satellite constellation for bushfire prevention, mitigation and resilience. ANU expertise in global fuel hazard spatial data augments international commercial and government fire detection initiatives. Space-proven Australian detector technology becomes available for national and commercial small satellite missions. This report comprises two parts: Part 1: OzFuel Mission Requirements developed by Nicolas Younes and Marta Yebra from the ANU Fenner School of Environment & Society. The report introduces the OzFuel mission, the need for a dedicated fuel monitoring mission, and the remote sensing requirements for a pathfinder mission. Part 2: OzFuel Technical Overview developed by Rob Sharp from the ANU Advanced Instrumentation & Technology Centre. The overview outlines the technical design and payload options for the OzFuel-1mission. The climate crisis over the past decade culminated in the unprecedented 2019/2020 Australian bushfire conditions that were more catastrophic than expected or modelled. The risk of larger and more frequent mega-fires is only going to increase in future years. Allocating further ground resources to suppress fires is extremely costly and dangerous, and needs to be augmented with more effective prediction, prevention and mitigation strategies before an unforeseen ignition event burns out of control. One of the most crucial aspects of fire prevention is understanding vegetative fuel state. The 2020 Royal Commission into National Natural Disasters highlights the need for whole-of-continent visibility of vegetative fuel state – how much fuel there is and how dry it is. Australia relies on foreign satellite data which is not optimised for measuring our unique bush landscape. The growing need forsovereign satellites to remotely sense Australia’s unique vegetation has been supported by recommendations from government, agencies, industry and research institutions.Geoscience Australi

Tectonic episodicity in the greater Himalaya, NW India

The Himalaya is an orogenic welt within the Alpine-Tethyan mountain chain. The extant tectonic model for the Himalayan terrane stack entails continuous post-collisional convergence and persistent heating during burial and subsequent exhumation. An alternative hypothesis to this "continuous evolution" scenario involves episodic tectonic mode switching, a concept that has been documented in other orogens along the Alpine-Tethyan belt. This thesis therefore tests the possibility that there is episodic mode switching in respect to the evolution of the Greater Himalaya in its topographically high crystalline core, in Himachal Pradesh, NW India. The approach adopted employs microstructurally-focused 40Ar/39Ar geochronology, across key tectonic contacts and geological terranes of the Greater Himalaya, to constrain the timing and temperature evolution of individual deformation and metamorphic events. In the leading edge of the Greater Himalaya, geological structures in the Shimla klippe and Narkanda syncline were examined with the intent of structurally and geochronologically characterising the Main Central Thrust (MCT). However, argon geochronology of fabrics structurally above and below the tectonic contact revealed that these fabrics formed in the Eocene period or earlier, during the Mesozoic. Therefore, these shear zones, although they had previously been intimately linked with the MCT, are in fact significantly older structures. In the root zone of the Phojal fold nappe, microstructural analysis revealed the influence of two distinct thermal excursions at upper greenschist grade that occurred towards the cessation of spatially associated ductile shearing events. Mica samples from the recumbently folded fabric of the supposed 'nappe' yield complex argon apparent age spectra, from which it can be inferred that: i) there were two distinct extensional shearing events that had terminated respectively by ~35 Ma and ~24-21 Ma; ii) the Phojal fold appears to have developed some time in the Oligocene, and not in the Miocene as is now supposed; iii) the fold recumbently folded the first Eocene-Oligocene ductile shear zone before itself being overprinted and attenuated in the Miocene by extensional ductile shear zones; iv) tectonic sequence diagrams inferred from those rocks are incompatible with a structural location in the hanging wall close to a thrust. Consequently the MCT as described today was not evident as a thrust in the Kullu region during the formation of the Phojal fold. From the character and timing of tectonic sequences, it is inferred that the fold geometry developed as a result of tectonic mode switching. Argon diffusion modelling supports the conclusion based on microstructures that the M1 and M2 metamorphic events cannot have occurred as part of a single protracted heating event. There must have been cooling (and possible exhumation) in between. The research in this thesis demonstrates that the tectonic evolution of the Greater Himalaya is consistent with multiple episodes of crustal shortening followed by regional extension events. The timing of the tectonic mode switches is broadly compatible with mode switches as observed in orogens elsewhere along the Alpine-Tethyan chain