18 Apr 2020

New GCA paper: Volcanic eruptions triggered repeated marine anoxia and reveal global-scale feedbacks during the Permian-Triassic mass extinction 250 million yeers ago

The largest animal extinction event in recorded history occurred 251 Ma at the Permian-Triassic boundary coinciding with expansive marine anoxia. In a new study, led by postdoc Feifei Zhang, of a greatly expanded dolomite section from the Carnic Alps, Austria, marine anoxia is found to have expanded in two pulses separated by ~100,000 years. Global […]

1 Mar 2020

Expansive ocean anoxia during the Late Devonian Hangenberg event

Marine animal extinction events have occurred episodically over the past 550 million years with expansive marine anoxia as the proximate kill mechanism. New evidence from a carbonate section in South China (Long’an) shows that the Late Devonian Hangenberg event should be counted as one such events. Postdoc Feifei Zhang have analyzed uranium isotopes in a […]

22 Oct 2019

Forskerzonen: Mystery about animals in ancient anoxic oceans resolved

The newly discovered ocean ventilation events in the 500 million year old Alum shale ocean is described in Danish on Forskerzonen: Videnskab.dk 

12 Sep 2019

Tracking the global dynamics of Earth’s oxygen and biological production in deep time

In an article published online in PNAS Tuesday Sep 10th, we have demonstrated how a combination of metal isotope analyses in marine sedimentary rocks can constrain the global scale feedbacks between atmospheric oxygen, seafloor oxygenation, and marine biological production. The relationship between O2 and animal life turns out to be more entangled than first thought. […]

12 Aug 2019

New study solves 500 million year old animal breathing paradox

Animals breath oxygen, but fossils of some of the earliest animals are found in what appears to be anoxic parts of the oceans. New research, led by Tais W. Dahl in collaboration with researchers from GEUS and Royal Holloway University London, shows that fluctuations in O2 availability at the seafloor allowed benthic animals to invade […]

7 Aug 2019

Tais speaks at Teacher’s conference “Big Bang to Science”

The Niels Bohr Institute invites teachers to a conference called “Big Bang til Naturfag” (Big Bang to Science) to learn more about the history of the universe, our planet and the evolution life.  On Aug 6, 2019 Tais W. Dahl is giving the talk entitled “Det tidligste liv” (The earliest life). Hereafter, Morten Allentoft from […]

25 Jun 2019

Susanne and Tais visit Potsdam Institut für Klima

Invited by Dr. Philipp Porada, Susanne and Tais will be visiting to expand our model understanding on how early plants affected the composition of the atmosphere and oceans. Thursday at 14:00, Tais will give a lecture entitled: “Evidence for the Great Mid-Paleozoic Transition linked to the colonizations of land” at Potsdam Institute for Climate Impact […]

8 May 2019
10 Apr 2019

Teaching at the Climate-KIC PhD course in Copenhagen

Geoengineering is one the key climate mitigation strategies, and even though humanity will need to cut down greenhouse hase emissions, several geoengineering mitigation strategies may develop into billion dollar businesses in the coming decades… Tais W. Dahl will be lecturing at this year’s Climate-KIC PhD course in Copenhagen on Friday July 5th. 

13 Feb 2019

Julius C. Havsteen defends his MSc thesis on Feb 20

Julius C. Havsteen, MSc Thesis DefenseCalibrating the d238U paleoredox proxy, using calcitic brachiopods, across the late Silurian Lau eventSupervisors: Tais W. Dahl, IGNExternal examiner: Niels Schovsbo, GEUS Geological Museum, Auditorium. Wednesday February 20, 2019 at 10–11. Øster Voldgade 5–7, 1350 Copenhagen K, Denmark