Earth’s magnetic field may have sparked mass extinctions

At several times in Earth’s history, mass extinctions have come close to wiping life out altogether. The reasons for these catastrophes are still unclear – they’ve been blamed on everything from asteroid impacts to cosmic ray blasts. But a new study has found that our planet itself could have a surprising hand in these disasters.

Research recently published in Earth and Planetary Science Letters suggests that reversals of the Earth’s magnetic field may have sparked mass extinctions in the past by stripping oxygen from the atmosphere.

Field Flips

The Earth’s natural magnetic field, generated in the liquid outer core, spontaneously changes direction every 500,000 years or so. Known as geomagnetic reversals, these processes cause the field’s north and south poles to swap places.

Normally, the Earth’s magnetic field acts like a shield around the atmosphere, protecting it from the damaging effects of the solar wind (the supersonic stream of charged particles emitted by the sun​). During a geomagnetic reversal, however, the field weakens dramatically, exposing the atmosphere to the full force of the solar wind – and causing oxygen ions to be stripped off into space.

This much was already known. But in the recent study, a team led by Yong Wei of the Chinese Academy of Sciences set out to discover if the oxygen lost during geomagnetic reversals could bring about mass extinctions.

It had long been known that mass extinctions are often accompanied by both an increase in the rate of geomagnetic reversals and a decrease in atmospheric oxygen levels (one of the potential drivers of mass extinctions). The researchers’ goal was to determine if geomagnetic reversals could actually have caused such oxygen loss – and therefore potentially have caused mass extinctions, too.

Oxygen Depletion

Wei and colleagues focused on the “Triassic-Jurassic” mass extinction of 200m years ago, in which up to 84% of all species on Earth perished. Independent studies had already shown that, during this extinction, the geomagnetic reversal rate doubled, and the amount of atmospheric oxygen simultaneously dropped by 9 percent. This oxygen drop is one of the possible reasons for the extinction.

Using a computer model, Wei and his team concluded that geomagetic reversals stripped at least 218 trillion tons of oxygen from the Earth’s atmosphere during the Triassic-Jurassic extinction – or 4.5 percent of the total amount. This indicates that at least half of the 9 percent oxygen drop that occurred during the extinction could have been caused by geomagnetic reversals alone – more than enough, the study’s authors say, to have played a major role in the die-off.

This theory may explain even deadlier mass extinctions. Study coauthor Markus Fraenz of the Max Planck Institute for Solar System Research said that the oxygen loss caused by geomagnetic reversals could also have caused the end-Permian mass extinction (also known as the “Great Dying”), in which up to 97% of all species were wiped out.

Perhaps then, alongside the meteoric collisions, supernovae explosions and volcanic eruptions – which have variously been proposed to explain mass extinctions – it’s time to add another suspect. The invisible fluctuations of a physical field might not be as cinematic, but their consequences throughout history may have been just as dire.

http://blogs.discovermagazine.com/d-brief/2014/06/10/earths-magnetic-flips-may-triggered-mass-extinctions/

Well that's a little scary. We are do for a magnetic flip NOW. Actually my thoughts on what the flip would do involved upper atmospheric disturbance.

http://www.i-sis.org.uk/O2DroppingFasterThanCO2Rising.php

This is a fascinating new theory to me. hmmm.... Ok what are all the things that remove O2 from the atmosphere?

ok, the climate greenies are going to kill us all off with their "cure".

The case for extracting carbon from the atmosphere, via biochar or other methods, may get a prominent boost in April when the UN’s Intergovernmental Panel on Climate Change (IPCC) issues the next installment of its Fifth Assessment Report

http://e360.yale.edu/feature/as_uses_of_biochar_expand_climate_benefits_still_uncertain/2730/

The story goes that charcoal buried in the soil is stable for thousands if not hundreds of thousands of years and increases crop yields. The proposal to grow crops on hundreds of millions of hectares to be turned into buried ‘biochar’ is therefore widely seen as a “carbon negative” initiative that could save the climate and boost food production.

That story is fast unravelling. Biochar is not what it is hyped up to be, and implementing the biochar initiative could be dangerous, basically because saving the climate turns out to be not just about curbing the rise of CO2 in the atmosphere that can be achieved by burying carbon in the soil, it is also about keeping oxygen (O2) levels up. Keeping O2 levels up is what only green plants on land and phytoplankton at sea can do, by splitting water to regenerate O2 while fixing CO2 to feed the rest of the biosphere [1] (Living with Oxygen, SiS 43).

Climate scientists have only discovered within the past decade that O2 is depleting faster than the rise in CO2, both on land and in the sea [2, 3] (O2 Dropping Faster than CO2 Rising, and Warming Oceans Starved of Oxygen, SiS 44). Furthermore, the acceleration of deforestation spurred by the biofuels boom since 2003 appears to coincide with a substantial steepening of the O2 decline. Turning trees into charcoal in a hurry could be the surest way to precipitate an oxygen crisis from which we may never recover.
http://www.i-sis.org.uk/bewareTheBiocharInitiative.php

Back to the topic. I hijacked my own thread but since im talking with myself its ok lol

So I was curious as to how the magnetic poles effected oxygen.

The plasmasphere is not really spherical but a doughnut-shaped region (a torus) with the hole aligned with Earth's magnetic axis. [In this case the use of the suffix -sphere is more in the figurative sense of a "sphere of influence".] The Earth's plasmasphere is made of just that, a plasma, the fourth state of matter. (Test your skills on sorting the states of matter with the Matter Sorter.) This plasma is composed mostly of hydrogen ions (protons) and electrons. It has a very sharp edge called the plasmapause. The outer edge of this doughnut over the equator is usually some 4 to 6 Earth radii from the center of the Earth or 12,000-20,000 miles (19,000-32,000 km) above the surface. The plasmasphere is essentially an extension of the ionosphere. Inside of the plasmapause, geomagnetic field lines rotate with the Earth. The inner edge of the plasmasphere is taken as the altitude at which protons replace oxygen as the dominant species in the ionospheric plasma which usually occurs at about 600 miles (1000 km) altitude. The plasmasphere can also be considered to be a structure within the magnetosphere.
http://www.albany.edu/faculty/rgk/atm101/structur.htm

So when the magnetic field flips, it first is disorganized and we are exposed, it doesn't have much strength to protect us. I wonder if this is why we loose O2, the sun blasting us with protons. hmmm

last flip was...

A brief complete reversal, known as the Laschamp event, occurred only 41,000 years ago during the last glacial period. That reversal lasted only about 440 years with the actual change of polarity lasting around 250 years.
http://en.wikipedia.org/wiki/Geomagnetic_reversal