The Mystery of Antarctica’s Missing Meteorites
Hiding deep under the ice, iron meteorites could hold clues to the solar system’s past.
Robin George Andrews, The Atlantic, Feb. 2019
https://www.theatlantic.com/science/archive/2019/02/hunting-for-antarcticas-lost-meteorites/583564/
Yours,
Paul H.
Wednesday, 27 February 2019
Saturday, 16 February 2019
Oceanic and Atmospheric Cooling Started Before Start of Younger Dryas 16FEB2019
Oceanic and Atmospheric Cooling Started Before Start of Younger Dryas
Hi,
While reading on a slow Friday afternoon,
I came across the below paper.
Levac, E., Sandercombe, S. and Chmura, G.L., 2018.
The Younger Dryas in palynological records from
the northern Northwest Atlantic: Does the terrestrial
record lag the marine and air records?.
Palaeogeography, Palaeoclimatology, Palaeoecology,
490, pp.269-279.
In part the the abstract states:
“Major changes in both pollen and dinocyst
assemblages are recorded during the Younger
Dryas in Bay of Islands and are associated with
large drops in air and sea surface temperatures,
and sea surface salinity. The changes in
vegetation are similar with those observed at
other sites in Newfoundland.”
“Sea-surface and air temperatures started
cooling 250 and 110 years before the start of
the YD, hence there is a 140 years delay
between ocean and atmosphere.”
On page 277 of Levac et al. (2018):
“However, we were not expecting a cooling trend
(in sea-surface and air temperatures) that started
before the recorded YD period.”
and
“Not only did sea-surface and air temperatures start
to deteriorate before the start of the YD (respectively
250 years and 110 years before the YD), we also
see a 110 year-lag between the changes in air
temperatures and pollen assemblages.”
and
..and we suggest that the decrease in air
temperatures in eastern Canada started before
the YD period.”
Basically, the cooling trend associated with the
Younger Dryas (YD) actually started before the
official start of the YD period, the time of
the hypothesized YD impact.
How can an extraterrestrial impact effect climate
before it even happens?
Yours,
Paul H.
Thursday, 14 February 2019
A Possible Second Large Subglacial Impact Crater in Northwest Greenland 14FEB2019
A Possible Second Large Subglacial Impact Crater in Northwest Greenland
Scientist May Have Discovered Massive Crater
Under Greenland Ice Sheet, Daily Beast, Feb. 2019
https://www.thedailybeast.com/scientist-may-have-discovered-massive-crater-under-greenland-ice-sheet
Photos: Craters Hidden Beneath the Greenland
Ice Sheet, Live Science, February 12, 2019
The open access paper is:
Joseph A. MacGregor, William F. Bottke, Jr., Mark
A. Fahnestock, Jeremy P. Harbeck, Kurt H. Kjær,
John D. Paden, David E. Stillman, and Michael
Studinger, 2019, A Possible Second Large
Subglacial Impact Crater in Northwest Greenland
First published: 11 February 2019
The paper states:
"Based on the dated radiostratigraphy of the Greenland
Ice Sheet, available for pre-2014 radar data only, the
ice overlying the structure is at least 79 ka old (Figures
1e–1h; MacGregor et al., 2015)."
Yours,
Paul H.
Ocean Drilling Perspectives on Meteorite Impacts 14FEB2019
Ocean Drilling Perspectives on Meteorite Impacts
Christopher Lowery, Joanna V. Morgan, Sean P. S. Gulick,
Timothy J. Bralower, Gail Christeson, Expedition 364 Scientists,
2018, Ocean Drilling Perspectives on Meteorite Impacts
Created on August 08, 2018, Last edited on December 03, 2018
Supplemental materials: https://osf.io/u287b/
Yours,
Paul H.
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