Quantifying the Release of Climate-Active Gases by Large Meteorite Impacts With a Case Study of Chicxulub
Quantifying the Release of Climate-Active Gases by Large Meteorite Impacts With a Case Study of Chicxulub
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DOI：
10.1002/2017gl074879
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发表时间：
2017-10-28
影响因子：
5.2
通讯作者：
Morgan, Joanna
中科院分区：
文献类型：
--
作者：
Artemieva, Natalia;Morgan, Joanna
在地球的整个历史上，潜在的危险小行星和彗星都曾撞击过地球，在奇克苏鲁伯撞击的情况下，带来了灾难性的后果。在这里，我们重新研究使一种影响产生全球影响的机制之一--从沉积岩中释放气候活跃的气体。我们使用SOVA程序，并在撞击后足够长的时间内模拟喷出的物质，以量化达到足够高的高度(25公里)的气体的体积，从而产生全球后果。我们改变冲击角、沉积物厚度和孔隙度、水深和脱挥发的冲击压力，并以无量纲的形式呈现结果，以便可以估计任何对沉积目标的影响所释放的气体。使用对希克苏鲁伯撞击角度和目标成分的新限制，我们估计喷出了325+/-130GT硫和425+/-160GT二氧化碳，并对全球气候产生了严重变化。通俗易懂的语言摘要在地球历史上，潜在危险的小行星和彗星撞击地球，在66百万里头的希克苏鲁伯撞击事件中造成了灾难性的后果。在这里，我们重新研究了使撞击产生全球影响的机制之一--在高速撞击后，陆地沉积岩释放出气候活跃的气体。我们估计有325+/-130GT的硫和425+/-160GT的CO2以1公里/S的速度排放到大气中。这些数字必须用于全球气候模式，以量化太阳辐射、地表温度和生物群胁迫条件持续时间的可能变化。
Potentially hazardous asteroids and comets have hit Earth throughout its history, with catastrophic consequences in the case of the Chicxulub impact. Here we reexamine one of the mechanisms that allow an impact to have a global effect-the release of climate-active gases from sedimentary rocks. We use the SOVA hydrocode and model ejected materials for a sufficient time after impact to quantify the volume of gases that reach high enough altitudes (> 25 km) to have global consequences. We vary impact angle, sediment thickness and porosity, water depth, and shock pressure for devolatilization and present the results in a dimensionless form so that the released gases can be estimated for any impact into a sedimentary target. Using new constraints on the Chicxulub impact angle and target composition, we estimate that 325 +/- 130 Gt of sulfur and 425 +/- 160 Gt CO2 were ejected and produced severe changes to the global climate.Plain language Summary Potentially hazardous asteroids and comets have hit Earth throughout its history, with catastrophic consequences in the case of the Chicxulub impact 66 Myr ago. Here we reexamine one of the mechanisms that allow an impact to have a global effect-the release of climate-active gases from terrestrial sedimentary rocks after the high-velocity impact. We estimate that 325 +/- 130 Gt of sulfur and 425 +/- 160 Gt CO2 were ejected into the atmosphere at velocities > 1 km/s. These numbers have to be used in global climate models to quantify possible changes of solar irradiation, surface temperature, and duration of stressful conditions for biota.