Volcanoes Are Evil


During the Cretaceous our mammalian relatives were small and puny. They wandered around and tried not to become a warm snack for the reptiles that ruled the day. Insects began to diversify to eventually become the diverse group we now know and occasionally dip into chocolate. In the seas, rays, sharks, and all the bony fishes began to dominate and replace the way cooler cephalopods. Large marine reptiles still roamed the seas as opposed to just a lake in Scotland. The continents were still relatively close but rock n’ roll, drugs, and women were soon to split them. The Atlantic was a mere young whipper snapper barely a few hundred kilometers big.

Two spectacularly awful events occurred in the ocean. Ocean anoxic event 1 (120mya) and 2 (93 mya). Rather unshockingly, the complete lack of oxygen in the oceans led to major extinctions. But what caused the OAE? New evidence strengthens the link between OAE2 and volcanism (but not Vulcans whose large brains are also known to cause major oxygen depletion).

In one scenario, the intense volcanic discharge likely changed the chemistry of the ocean and atmosphere. This may have provided micronutrients to phytoplankton resulting in ocean wide blooms. All of the sinking and rotting plankton eventually decayed on the ocean floor and stripped oxygen in the process.


Volcanoes disgorged clouds of CO2 to the atmosphere, warming the climate to the extent that Earth’s ocean circulation system ground to a near-halt. Beyond the surface layers, water was no longer turned over and anoxia was the result.

Either way volcanoes are evil and an enemy of our salty friends.

Turgeon, S.C., Creaser, R.A. (2008). Cretaceous oceanic anoxic event 2 triggered by a massive magmatic episode. Nature, 454(7202), 323-326. DOI: 10.1038/nature07076

Dr. M (1801 Posts)

Craig McClain is the Executive Director of the Lousiana University Marine Consortium. He has conducted deep-sea research for 20 years and published over 50 papers in the area. He has participated in and led dozens of oceanographic expeditions taken him to the Antarctic and the most remote regions of the Pacific and Atlantic. Craig’s research focuses on how energy drives the biology of marine invertebrates from individuals to ecosystems, specifically, seeking to uncover how organisms are adapted to different levels of carbon availability, i.e. food, and how this determines the kinds and number of species in different parts of the oceans. Additionally, Craig is obsessed with the size of things. Sometimes this translated into actually scientific research. Craig’s research has been featured on National Public Radio, Discovery Channel, Fox News, National Geographic and ABC News. In addition to his scientific research, Craig also advocates the need for scientists to connect with the public and is the founder and chief editor of the acclaimed Deep-Sea News (http://deepseanews.com/), a popular ocean-themed blog that has won numerous awards. His writing has been featured in Cosmos, Science Illustrated, American Scientist, Wired, Mental Floss, and the Open Lab: The Best Science Writing on the Web.

10 Replies to “Volcanoes Are Evil”

  1. “100% pure fiction…what a ignorant little fool man is”

    What a fool this guy is…

  2. Evil?! Just because your little salty friends can’t be bothered to make a good emergency plan? All species should be prepared for flood basalts, it’s just good sense.

    Why, without volcanoes, none of us would be here! You punk metazoans should show a little respect.

  3. d m: I don’t believe in it anyway.
    CR McClain: What?
    d m: volcanoes.
    CR McClain: Just a conspiracy of geologists, then?

  4. “Even though I know I will regret this later…exactly what part is ‘100% Pure Fiction'”

    Anything spouted by the Bush administration, especially about offshore drilling….

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