Harvard scientists are now involved in the Younger Dryas Boundary Event controversy. A PNAS paper has reopened the case in a dramatic fashion and George Howard adds a touch of sarcastic humour with a spoof - see http://cosmictusk.com/petaev_platinum_harvard_younger_dryas_impact_aster... and http://cosmictusk.com/paetev_harvard_platinumyounger_dryas_comet_clovis_...
Excellent post by Hossein Turner at http://hozturner.blogspot.co.uk/2013/07/the-great-comet.html ... a fresh insight into the Great Comets of the Ancient World, inspired no doubt by comet ISON and its appearance later in the year. Comets are common on rock art - but not always recognised as such. However, the fact that many petroglyphs have features in common with Chinese comets as illustrated on the Silk Manuscripts (drawn up between 200BC and 9AD) may serve to shed some new light on the origin and meaning of some of the etchings on rock faces.
At http://tallbloke.wordpress.com/2013/07/01/2013-chelyabinsk-meteor-larges... ... the 2013 Russian meteor, or fireball, is the largest ever recorded by CTBTO seismic monitoring (infrasound sensors) and a paper on the subject is now available. It raises some interesting questions. If there had been a lot of meteors in the past how would scientists know that they had occurred?
At http://phys.org/print291614362.html ... this is all part of CAGW hype so may be complete waffle without much substance - but interesting in the context of the last Ice Age and how it all hangs together with a dollop of circular reasoning as far as sea levels and ice sheets are concerned. The paper is published in Nature Geoscience and looked at fossilised coral in the Caribbean - which is purported to tell us about historical rises in sea levels.
At http://phys.org/print291396902.html ... we learn that more than ten thousand asteroids and comets that can pass near the Earth have now been discovered. They range in size from a few feet across to 41km across. Asteroid 2013MZ5 is about 300m across - so fairly small on the average. In the 20th century the add up rate was small - just 500 by 1998. After that date, with the advent of super telescopes, that figure has escalated.
At a recent SIS study group meeting the Eskimo claim they could hear aurora was discussed, which has recently been verified by scientists. They said it sounded like the gods were treading on ice packed snow, with a sort of 'ch ch' sound, and a connection was made with various gods of old, such as Cuchulainn (Ireland) and Kukulcan (South America) and so on. In the context of the 776AD event there is an interesting parallel.
At http://phys.org/print290254727.html ... rock samples from Tunguska appear to be meteoric in origin according to a paper in Planetary and Space Science (5th June 2013) by researchers from the US, Germany, and the Ukraine. It is supposed, from this, that a meteor exploded in the atmosphere over Siberia in 1908 (much like the Feb 2013 Russian meteor - but presumably of greater magnitude, or lower altitude).
Nice post at www.q-mag.org/stonesfallingfro/index.html ... on historical accounts of stones falling out of the sky and the resistance by scientists in Europe to the very idea. It begins with a huge iron meteorite in Argentina to get the ball rolling and a rain of stones over Rome during the Punic wars. The Chinese historian MaDuadin compiled reports of meteorite falls in China over 200 years - 337 fell between 700BC and 1920AD (presumably large ones).
As noted a week or so ago, George Howard at http://cosmictusk.com/wittke_pnas_younger_dryas_clovis_comet/ ... posted news of a fresh paper on the YD event. So far he has only the news release and list of co-authors (which include himself). However, another of the co-author's, Kenneth Tankersley of the University of Cincinatti, has been giving his pennyworth -see www.world-science.net/othernews/130520_mammoth.htm
Interesting piece of geology this - the remains of an Alpine forest found in a clay layer. How long did it take the clay to form?