H2020Индивидуална стипендия2017–2020

ImpChar · Using charcoals as a proxy to estimate energy released from small Impact cratering processes

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2017-10-01 → 2020-11-29
Финансиране от ЕС: 195 455 €
Участници: 1
Схема: MSCA-IF-EF-ST

Линиите свързват координатора с партньорите.

Накратко на български

Овъглените останки от организми в малки кратери, като тези в Естония и Полша, се анализират, за да се изчисли топлинната енергия при удари на астероиди. Това помага за по-точното разграничаване на метеоритни удари от горски пожари и оценка на рисковете за населените райони.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

Using charcoals as a proxy to estimate energy released from small Impact cratering processes

Asteroid impacts represent a natural hazard capable of causing significant damage on the Earth, as evidenced by the impact of a body that formed the 180-km wide Chixulub crater causing extensive environmental perturbations. Estimates of the current impact flux on Earth show that within the lifetime of our species it is likely that a significant asteroid impact will hit a populated area. Existing observational and modelling approaches have found it hard to quantify the thermal energy release from small impact cratering processes. Most methods used to study and characterise small impact craters and the energy processes associated with them are based on approaches used to assess large impact craters with high temperature transitions, that are rarely present in small impact craters in unconsolidated target rocks. The aim of ImpCHAR was to use properties of dead bodies of organisms killed during the fall of the asteroid and preserved within their ejecta blanket as a char to understand the energy release from small impacts. We do it by a set of targeted field work within proximal ejecta blanket of confirmed impact craters up to 120 m in diameter (Kaali in Estonia, Morasko in Poland and Whitecourt in Kanada), a couple of unconfirmed structures (Ilumetsa in Estonia and Tor in Sweden), a set of laboratory experiments mimicking different scenarios of charcoal production. Here we show that the reflective properties of charcoals found in the proximal ejecta of small impact craters are distinguishable from those produced by wildfires. We reveal that: 1) the proximal ejecta blanket of small impact craters is locally hot, and 2) finding charcoal with specific reflective properties within proximal ejecta can be used to identify the meteorite impact origin of small craters. This study will enable us to better quantify the impact rate and understand the full spectrum of possible interactions of impactors with the atmosphere and Earth’s surface, so that we can adequately prepare for the future impact.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

Over the last half a century there has been much debate over the quantities and mechanisms of thermal energy release during impacts of small asteroids such as Tunguska event (Russia) or Kaali craters. This has been caused in a large part by the fact that the existing observational and modelling approaches have focused on large impact craters that generate high temperature/pressure transitions which leave noticeable signatures in the rocks they affect. However, small impacts craters developed in unconsolidated materials have not been thought to leave long lasting traces of the thermal energy released during their formation. Recently however, Losiak et al. (2016) found charcoal buried within ejecta blanket of Kaali Main crater where sedimentological analyses and 14C dating suggest that the charcoal was formed at the same time as the craters within which they were found. Subsequently Losiak identified charcoal in Kaali 2/8, Ilumetsa Small, Ilumetsa Large and the Morasko Main craters, indicating that charcoal is not restricted to a single crater, single impact or single location. Project ImpCHAR will use a novel analysis method that measures the reflectance properties of charcoal, which has been recently shown to relate to the energy that created it. ImpCHAR will use this method to determine the heating regime from which the chars were created. In order to achieve this Project ImpCHAR will experimentally recreate the heating conditions in a laboratory setting in order to determine the most likely mechanism of charcoal formation. This will allow developing a method of unequivocally identifying small impact craters developed in vegetated unconsolidated sediments: up to this point most of those kinds of structures could be identified only based on circumstantial evidence of co-existing crater-like shape and occurrence of meteorites. Additionally, ImpCHAR will critically disentangle debate surrounding the energy release during formation of small impact craters.

Оригинален текст от CORDIS (на английски).

Участници

THE UNIVERSITY OF EXETER · ExeterКоординаторОбединеното кралство