Submitted by avogadros_number t3_112fbo1 in science
[removed]
[removed]
[removed]
https://en.wikipedia.org/wiki/Cenomanian-Turonian_boundary_event
> Although the cause is still uncertain, the result starved the Earth's oceans of oxygen for nearly half a million years, causing the extinction of approximately 27 percent of marine invertebrates, including certain planktic and benthic foraminifera, mollusks, bivalves, dinoflagellates and calcareous nannofossils.[16] The global environmental disturbance that resulted in these conditions increased atmospheric and oceanic temperatures.
[removed]
It seems to me volcanoes are easily one of the biggest threats to the planet and generally underrated for vastly less common things like big meteors.
Who’s ready for round 3?? [looking nervously at dying coral reefs]
[deleted]
Perhaps something to do with most fossils being land species, a large dropoff in marine species may not be as noticeable overall
FYI the link you provide says nothing about diatoms, benthic or planktonic.
However, in "The origin of Cretaceous black shales: a change in the surface ocean ecosystem and its triggers (2015)" the authors state
>During OAE 2, up to 25% of marine invertebrate species became extinct
They absolutely are. Of all of the mass extinction events and minor extinction events, one of them (the end-Cretaceous) is more commonly attributed to bolide impact, though not without prior effects from the Deccan Traps. The End-Permian (Siberian Traps), and End-Triassic (Central Atlantic Volcanic Province - CAMP) are certainly attributed to volcanism, as are a number of other extinction events such as AOE 2 and others. Not all large impact events lead to extinctions or mass extinctions (> 75% of all species go extinct within a relatively short geological time span). For example, the Manicouagan Impact Crater, located in Quebec, Canada has a diameter of ~100 km and occurred more than 12 million years before the end of the Triassic with no extinctions associated with the event.
The greatest cause of extinction events - mass or otherwise, whether from volcanism, impact events, orbital cycles, etc. results from the subsequent changes in atmospheric and ocean chemistry. This doesn't bode well for our current climate trajectory.
>During the Jurassic and Cretaceous, global events of widespread low-oxygen conditions (Oceanic Anoxic Events) were recorded in marine strata associated to major perturbations in the carbon cycle. These disturbances were linked to rapid global warming, probably caused by a release of carbon dioxide in the atmosphere due to degassing related to large-scale volcanism, dissociation of methane hydrates and thermogenic methane.
>Many authors have studied the Oceanic Anoxic Events (OAEs) following the original definition by Schlanger and Jenkyns (1976). Nine OAEs are recognized as of global significance and three of them are considered as major events: T-OAE, OAE1a and OAE2. The first, also called Toarcian OAE or Posidonienschiefer event, occurred in the Early Jurassic (~183 Ma) and was first identified by Jenkyns (1980) in northern Europe. The second, also called early Aptian OAE or Selli Event, occurred in the late Early Cretaceous (~120 Ma) and was first observed by Coccioni et al. (1987) in Italy. The third global event, also called Cenomanian – Turonian OAE or Bonarelli Event, occurred in the early Late Cretaceous (~93 Ma) and was noticed by Schlanger and Jenkyns (1976) when comparing subsurface data from the Deep Sea Drilling Project to outcrops; with the most famous being the Livello Bonarelli in the Umbrian Apennines of Italy.
This is why we need to ban volcanoes. Just say to no to volcano.
[deleted]
“But what about third breakfast sea extinction?” - tiny scientists
AutoModerator t1_j8jpzao wrote
Welcome to r/science! This is a heavily moderated subreddit in order to keep the discussion on science. However, we recognize that many people want to discuss how they feel the research relates to their own personal lives, so to give people a space to do that, personal anecdotes are allowed as responses to this comment. Any anecdotal comments elsewhere in the discussion will be removed and our normal comment rules apply to all other comments.
I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.