TERRESTRIAL IMPACT STRUCTURES, 2 Teile

The idea for this atlas was born already several years ago. Then, a precise topographic atlas presenting terrestrial impact craters, the scars of the impacts of solid bodies onto the Earth's surface, had not been established yet. This was astonishing, as such impacts had long been considered as the "most fundamental process on the surfaces of the terrestrial planets", as the late Eugene Shoemaker, one of the pioneers of impact geology, had put it. But when the first digital elevation data had been processed from the early phase of the TanDEM-X mission, they immediately showed their great potential for mapping applications. We were particularly excited, because the objective of this space-borne undertaking of generating a precise high-resolution digital elevation model for the entire solid surface of Earth would allow, for the first time, to map the morphology of all terrestrial impact structures with a topographic expression, in detail. What had been the limiting factor of the existing datasets for such an exercise in the past - no global coverage, data gaps, or data artefacts - would no longer hamper the cartographic work. Only very small impact craters below the resolution of the TanDEM-X data would escape recognition in the TanDEM-X maps.Patience, however, was required before the final TanDEM-X Digital Elevation Model (DEM) was released and access to the data for science applications was granted. In the meantime, we had investigated the workflow to present the topography of an impact structure and its environs by using Raw DEM scenes. Because our intention was not to merely publish a sequence of high-quality maps, our atlas concept foresaw to additionally provide short and concise, illustrated text sections for each impact structure. As two of us, Thomas Kenkmann and Wolf Uwe Reimold, have throughout their careers as impact geologists confirmed the impact origin of a considerable number of structures and participated in the studies of many more, these so-called

Band 1Preface 7Acknowledgments 8Small Bodies in the Solar System 9The Beginning 9Relics of Planetary Formation 10Impacts 11Hypervelocity Impacts 11Impact Crater Formation 12Contact and Compression 12Excavation 13Modification 14Shock Metamorphic Effects 15High-Pressure Polymorphs 16Impactites 17Tracing the Meteoritic Projectile in Impact Brecciasand Impact Melt Rock 17Terrestrial Impact Structures 19Earth's Impact Crater Record 19The Actual Impact Structure Record 19Impact Structure Parameterization 20Radar Remote Sensing 23Synthetic Aperture Radar 23SAR Interferometry 24The TanDEM-X Mission 26TanDEM-X Data Acquisition 27TanDEM-X DEM Generation 27TanDEM-X Maps of Impact Structures 30Data Fusion TanDEM-X / Multispectral Sensor 32The Atlas 337.1 Africa 35Overview 36Agoudal, Morocco 38Amguid, Algeria 40Aorounga, Chad 42Aouelloul, Mauretania 45Bosumtwi, Ghana 48BP, Libya 52Gweni Fada, Chad 56Kalkkop, South Africa 58Kamil, Egypt 60Kgagodi Basin, Botswana 62Libyan Desert Glass, Egypt 64Luizi, Democratic Republic of Congo 67Morokweng, South Africa 70Oasis, Libya 72Roter Kamm, Namibia 75Talemzane, Algeria 78Tenoumer, Mauretania 81Tin Bider, Algeria 84Tswaing, South Africa 86Vredefort, South Africa 89Impact Structures - Further Confirmation RequiredOuarkziz, Algeria 977.2 North/Central America 100Overview 101Ames, Oklahoma, United States 104Avak, Alaska, United States 104Beaverhead, Montana, United States 108Brent, Ontario, Canada 110Calvin, Michigan, United States 112Carswell, Saskatchewan, Canada 114Charlevoix, Quebec, Canada 116Chesapeake Bay, Virginia, United States 119Chicxulub, Mexico 122Clearwater East and Clearwater West, Quebec, Canada 126Cloud Creek, Wyoming, United States 130Couture, Quebec, Canada 132Crooked Creek, Missouri, United States 134Decaturville, Missouri, United States 136Decorah, Iowa, United States 138Deep Bay, Saskatchewan, Canada 140Des Plaines, Illinois, United States 142Douglas Crater Field, Wyoming, United States 144Eagle Butte, Alberta, Canada

Manfred Gottwald was educated in astronomy and physics at the Ludwig-Maxi­milians-Universität in Munich. After his Ph.D. in 1983 he worked in high-energy astrophysics for the European Space Agency and the Max-Planck Institute for Extraterrestrial Physics, studying objects far out in our galaxy and beyond. When he joined the German Aerospace Center at Oberpfaffenhofen, our solar system and Earth became the scientific topics of choice. At the Earth Observation Center he was involved in many space-borne missions investigating our atmosphere, our cryosphere and the terrestrial surface. Particularly challenging was his responsibility for the atmospheric science instrument SCIAMACHY on the European ENVISAT platform. Since the International Polar Year 2007/2008 he coordinated the national Earth Observation missions in support of polar science under the auspices of the World Meteorological Organization. This familiarized him with the TanDEM-X radar mission, whose high-resolution digital elevation model allowed Manfred to engage in impact craters, a field where astronomy meets geology.