Holocene Impact Working Group

The Holocene Impact Working Group (HIWG) is an ad hoc association of researchers from various geoscience disciplines who share the belief that large meteor impacts on Earth occurred more frequently during the Holocene epoch than is generally accepted. It was created as a follow-up to the Workshop on Comets/Asteroid Hazard held in the Canary Islands in December 2004, and according to German Wikipedia was founded in 2005 following a working meeting supported by the International Science Council. The group's hypotheses have attracted some press attention but have often been received with reservation or rejection by other scientists. The group's web presence is hosted and maintained by the Tsunami Laboratory of the Institute of Computational Mathematics and Mathematical Geophysics (ICMMG), Siberian Division, Russian Academy of Sciences, in Novosibirsk, Russia. The site is maintained by Dr. Viacheslav K. Gusiakov, Head of the Tsunami Laboratory, who is also listed as a member of the group. The website includes sections for home, purpose, members, activity, projects, data, expeditions, meetings, publications, links, and a reserved area not open to a wider audience, containing documents and data circulating between group members. As of January 2021, the group's members included Dallas Abbott (Lamont-Doherty Earth Observatory, New York, USA), Mike Baillie (Queen's University Belfast, UK), Edward Bryant (University of Wollongong, Australia), Richard Firestone (Lawrence Berkeley National Laboratory, USA), Viacheslav Gusiakov (Novosibirsk Tsunami Laboratory, Russia), Simon Haslett (Bath Spa University, UK), Dieter Kelletat (University of Duisburg-Essen, Germany), Bruce Masse (Los Alamos National Laboratory, USA), Anja Scheffers (Southern Cross University, Germany), and Vadim Simonenko (Russian Federal Nuclear Center, Snezhinsk, Russia). Former members include Dee Breger (Drexel University, USA, died 2016) and Marie-Agnès Courty (European Center for Prehistoric Research, Tautavel, France). One of the HIWG's approaches is to search for seafloor structures that might be impact craters. Meteorite impacts in the oceans can trigger very large tsunamis capable of washing ocean rocks and debris far inland onto adjacent coasts. By studying the thickness and orientation of these tsunami deposits, the group attempts to locate their origin and thus the site of possible impacts. V-shaped dune-like ridges (chevrons) are interpreted as geomorphological evidence for megatsunamis that might have been triggered by impact events (the cosmogenic tsunami hypothesis). However, the formation of these ridges by wind is generally considered the more plausible explanation. At one such location off the northwest coast of Australia in the Gulf of Carpentaria, two adjacent crater-like structures were found, named Tabban (12 km diameter) and Kanmare (18 km diameter) by the HIWG. According to the involved scientists, mineralogical traces (impact glasses) suggest the possibility that this could be the impact site of a small double asteroid that struck about 1,500 years ago and might have caused global cooling. However, volcanic eruptions are now considered the likely cause (see climate anomaly 536–550). Dallas Abbott and Edward Bryant proposed that a 15th-century impact occurred in the sea off New Zealand, leaving an impact structure they named the "Mahuika" crater. They cited Māori legends and geological evidence as indications. Tsunami researcher James Goff and colleagues rejected this hypothesis, stating there is no conclusive evidence for the impact hypothesis. Richard Firestone concluded, partly based on chevrons, that the Younger Dryas cold period was caused by an impact. Other geologists consider this interpretation untenable. The hypothesis that the Younger Dryas was the result of an impact was still controversially discussed in the scientific community at the end of the 2010s.

The Holocene Impact Working Group (HIWG) was created as a follow-up to the Workshop on Comets/Asteroid Hazard held in the Canary Islands in December 2004. According to German Wikipedia, the group was founded in 2005 following a working meeting supported by the International Science Council. It brought together researchers from different fields of geoscience who believed that Holocene comet impacts were more frequent in the recent past than the accepted view. The group's hypotheses have attracted some attention in the press but have often been received with reservation or rejection by other scientists. The group's website is hosted and maintained by the Tsunami Laboratory of the Institute of Computational Mathematics and Mathematical Geophysics (ICMMG), Siberian Division, Russian Academy of Sciences, in Novosibirsk, Russia. The site is maintained by Dr. Viacheslav K. Gusiakov, Head of the Tsunami Laboratory, who is also a member of the group. The website includes sections for home, purpose, members, activity, projects, data, expeditions, meetings, publications, links, and a reserved area not open to a wider audience, containing documents and data currently circulating between group members. As of January 2021, the group's members included Dallas Abbott (Lamont-Doherty Earth Observatory, New York, USA), Mike Baillie (Queen's University Belfast, UK), Edward Bryant (University of Wollongong, Australia), Richard Firestone (Lawrence Berkeley National Laboratory, USA), Viacheslav Gusiakov (Novosibirsk Tsunami Laboratory, Russia), Simon Haslett (Bath Spa University, UK), Dieter Kelletat (University of Duisburg-Essen, Germany), Bruce Masse (Los Alamos National Laboratory, USA), Anja Scheffers (Southern Cross University, Germany), and Vadim Simonenko (Russian Federal Nuclear Center, Snezhinsk, Russia). Former members include Dee Breger (Drexel University, USA, died 2016) and Marie-Agnès Courty (European Center for Prehistoric Research, Tautavel, France). One of the HIWG's approaches is to search for seafloor structures that might be impact craters. Meteorite impacts in the oceans can trigger very large tsunamis capable of washing ocean rocks and debris far inland onto adjacent coasts. By studying the thickness and orientation of these tsunami deposits, the group attempts to locate their origin and thus the site of possible impacts. V-shaped dune-like ridges (chevrons) are interpreted as geomorphological evidence for megatsunamis that might have been triggered by impact events (the cosmogenic tsunami hypothesis). However, the formation of these ridges by wind is generally considered the more plausible explanation. At one such location off the northwest coast of Australia in the Gulf of Carpentaria, two adjacent crater-like structures were found, named Tabban (12 km diameter) and Kanmare (18 km diameter) by the HIWG. According to the involved scientists, mineralogical traces (impact glasses) suggest the possibility that this could be the impact site of a small double asteroid that struck about 1,500 years ago and might have caused global cooling. However, volcanic eruptions are now considered the likely cause (see climate anomaly 536–550). Dallas Abbott and Edward Bryant proposed that a 15th-century impact occurred in the sea off New Zealand, leaving an impact structure they named the "Mahuika" crater. They cited Māori legends and geological evidence as indications. Tsunami researcher James Goff and colleagues rejected this hypothesis, stating there is no conclusive evidence for the impact hypothesis. Richard Firestone concluded, partly based on chevrons, that the Younger Dryas cold period was caused by an impact. Other geologists consider this interpretation untenable. The hypothesis that the Younger Dryas was the result of an impact was still controversially discussed in the scientific community at the end of the 2010s. Other alleged submarine crater structures found by the HIWG based on tsunami deposits include Grendel (North Sea, 18 km diameter), Quetzalcoatl (Caribbean, 10 km diameter), Burckle (Indian Ocean, 29 km diameter), Kangaroo (Indian Ocean, 5 km diameter), Joey (Indian Ocean, 4 km diameter), and Judge (Long Island Sound, 1 km diameter). Critics argue, partly based on astronomical calculations, that impacts capable of triggering such tsunamis occur too rarely to explain the number of craters proposed by the HIWG.

• 2005

  According to German Wikipedia, the group was founded in 2005 following a working meeting supported by the International Science Council.

• 2004

  Workshop on Comets/Asteroid Hazard held in the Canary Islands in December 2004, after which the HIWG was created as a follow-up.

1. 1Holocene Impact Working Grouptsun.sscc.ru
2. 2Holocene Impact Working Group - Abouttsun.sscc.ru
3. 3Holocene Impact Working Group - Wikidatawikidata.org
4. 4Holocene Impact Working Group - Wikipedia (German)de.wikipedia.org