The liming of the Earth after the Chicxulub large meteorite impact at the K/T boundary

Physics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

5420 Impact Phenomena (Includes Cratering)

Scientific paper

Shock metamorphism induced by large meteorite impacts on Earth decomposes sediments (carbonates: CaCO3, CaMg(CO3)2 and sulfates: CaSO4) into CaO, MgO, CO2 and SO2. For the Chicxulub case at the K/T boundary, up to 2850 Gt of CO2 and up to 550 Gt of SO2 were liberated into the atmosphere (Ivanov et al., 1996; Pierazzo et al., 1998; Gupta et al., 2002). Though numerous works have depicted the resulting environmental consequences of dispersing CO2, SO2, dust into the atmosphere (greenhouse warming, aerosol cooling, acid rains,...), no study has described the fate of the corresponding liberated CaO and MgO (up to 3718 Gt of CaO) in the atmosphere. Considering the high reactivity and the caustic nature of CaO (lime), we argue that spreading lime on the Earth surface increases the pH of natural waters up to 12.5. It would produce harmful environmental effects (carbonate and metal depletion in natural waters, oxydation of organic matter) and symptomatic isotopic 13C- and 18O-depleted, metal-enriched carbonates would form. Neutralization by the natural carbonate acid-base system (H2CO3/HCO3-/CO32-) of waters, by acid rains (H2CO3, H2SO4, HNO3) produced by the impact generated-CO2 and SO2, NOx and atmospheric CO2 pumping control the duration of this high pH effect on lands, while at the surface of the oceans, dilution and mixing with normal pH (? 8) seawater further reduce the duration of this high pH effect. The timescale of this high pH severe effects would be as short as a few months. As a conclusion, due to its high reactivity, lime rapidly neutralizes a significant part of the acidic atmospheric perturbation produced by the impact-liberated CO2, SO2, NOx. Ivanov et al., 1996 ; Geol. Soc. Amer. Spec. Pap., 307, 125-142. Pierazzo et al., 1998; J. Geophys. Res., Planet 103(E12), 28607-28625. Gupta et al., 2002; Earth Planet. Sci. Lett., 201, 1-12

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

The liming of the Earth after the Chicxulub large meteorite impact at the K/T boundary does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The liming of the Earth after the Chicxulub large meteorite impact at the K/T boundary, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The liming of the Earth after the Chicxulub large meteorite impact at the K/T boundary will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1687994

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.