Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Volcanoes, asteroids and mass extinctions

17.05.2004


Neither massive volcanic eruptions nor extraterrestrial impacts are sufficiently powerful on their own to cause mass extinctions of life on Earth, research by University of Leicester geologists suggests.



Instead, both events coincidentally occurring together may be required to cause the worst mass extinctions.

In the last 300 million years, life on Earth has suffered three major mass extinctions: those of the end-Permian, end-Triassic and end-Cretaceous periods.


The third of these, leading to the demise of the dinosaurs 65 million years ago, is believed to be caused by a meteorite colliding with the Earth, combined with the eruption of huge floods of basaltic lava.

Controversy rages over whether all three mass extinctions involve a similar combination of impact and volcanism, and if they did, whether this is due to random chance or whether there is any causal link between impact and volcanism.

Dr Rosalind White, Royal Society Dorothy Hodgkin Research Fellow, and Professor Andrew Saunders, both of the University of Leicester Department of Geology, recently looked at the statistical probability of any link between impact and eruptions to see whether it is credible that they occur during the same period by coincidence alone.

Their re-evaluation of the frequency of bolide (extraterrestrial) impacts and massive ‘flood basalt’ volcanism indicates that both events occur individually much more frequently than the incidence of mass extinctions.

This suggests that each, on its own, is not powerful enough to trigger a disastrous worldwide collapse of ecosystems that would lead to a mass extinction.

The occurrence of flood basalts (caused by the outpourings of basaltic lava) and bolide impact may both be necessary to lead to the largest mass extinctions the planet has known.

That begged the question as to what the likelihood was of the two events occurring over the same period, if they were not linked.

Here, Professor Saunders’ and Dr White’s statistical analysis showed that three random coincidences involving both impact and volcanism over the last 300 million years are likely, and there would not necessarily have to be any link between them.

They therefore suggest that theories implying that flood basalts are generated by bolide impacts are unnecessary and unproven.

Rosalind White explained the scale of events that cause flood basalts: “Massive continental flood basalt provinces occur when immense outpourings of basaltic lava are formed by localised partial melting in anomalously hot regions of the Earth’s mantle (the solid layer of rock between the Earth’s core and crust).

“A typical continental flood basalt would cover an area five times that of the UK, with lava exceeding 1 km in thickness, made up of hundreds of individual lava flows, each coming from an enormous volcanic eruption that may have lasted decades.

“Eruptions are separated by periods of inactivity that can last hundreds or thousands of years. The total time taken to erupt an entire continental flood basalt province is probably approximately 1-5 million years, though in most cases, the dating is not precise enough for us to know this duration accurately.”

A report on the research carried out by Dr Rosalind White and Professor Andrew Saunders is to be published later in the year by the geological journal Lithos.


Ather Mirza | University of Leicester
Further information:
http://www.le.ac.uk

More articles from Earth Sciences:

nachricht Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle
22.06.2018 | Technical University of Denmark

nachricht Polar ice may be softer than we thought
22.06.2018 | Eberhard Karls Universität Tübingen

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>