Scientists from Lamont-Doherty University and the University of Oxford have published research that links increased activity along earth’s major upper crustal plate boundaries with climate change. Both studies show that there could be a “complex feedback loop among ice ages, sea level changes” and “bursts of volcanic activity.”
This new research also confirms one of the most basic tenets of Plate Climatology theory (PCT) that suggests geologically based events and the climate are inextricably linked and are the most probable explanation for natural climate variations rather than manmade global warming.
A bold contention to be sure, but it is supported by this new and very solid research from two separate studies. Before we get to that, the following is a crash course on PCT:
“…periods of active Earth Tectonics and Volcanism can be correlated to periods of active climate change and climate-related events. To describe this new theory, the term “Plate Climatology” is proposed. In general increased tectonic activity, either locally or globally, equates to more faulting and volcanic activity primarily along tectonic plate boundaries / rift systems. Increased tectonic activity leads to more heat and fluid release from these active geological features into both the oceans and atmosphere. Altered heat and fluid input equates to climate change. This effect has been largely hidden from scientific investigation because the primary heat and fluid release is from two under-explored / under-monitored regions; deep oceans and sub-glacial polar ice caps.”
Details of this research from Lamont-Doherty / University of Oxford indicate that periods of fault movement, associated heat release, and associated CO2 release from major continental and oceanic plate boundaries “rift systems” (pictured above) are episodic.
During periods of increased rift system activity, significantly greater amounts of heat and CO2 are emitted into the oceans, and over time warm the atmosphere, altering the Earth’s climate, most notably melting much of the polar ice caps.
Water from melted polar ice caps raises sea level. When rift system activity decreases far less heat and CO2 is emitted, eventually the atmosphere cools and the polar ice caps expand back to their previous extent. Sea level falls. According to Live Science:
“Both studies suggest that there could be a complex feedback loop among ice ages, sea level changes and these bursts of volcanic activity. For instance, if volcanoes pick up their pace during an ice age, then carbon dioxide gas could warm the Earth and shrink the ice sheets. (Underwater volcanoes pump carbon dioxide into the ocean, just as their terrestrial cousins add climate-altering gases to the atmosphere.) However, no one knows how much gas would escape into the atmosphere from the oceans.
“In a broad sense, this reinforces the idea that the climate system and the solid Earth are connected and, in fact, may be thought of as a single system,” Katz said. “Not only do ice ages affect volcanism, but volcanism has a feedback effect on climate itself. We haven’t proved that yet, but it’s a tantalizing possibility.”
Tolstoy summarized the results from the East Pacific Rise and from closely monitored submarine eruptions around the world. The findings in Science, led by University of Oxford researcher John Crowley, are based on ocean floor surveys gathered by a Korean icebreaker in 2011 and 2013. Both studies rely on high-resolution spectral imaging of the seafloor, a remote-sensing technique that maps the surface in great detail.
“Both of these data sets have found a signal which is consistent with climate forcing of variations at mid-ocean ridges,” said Paul Asimow, a geology professor at the California Institute of Technology in Pasadena who was not involved in either study. “Now, apart from showing the effect is there, the other part that needs to be teased out is its consequences.”
The authors of each study are now searching for additional ice age signals at other spreading ridges, such as the Juan de Fuca Ridge offshore Washington and Oregon.”
The majority of this research, its conclusions, and explanations confirms many suppositions in the geologically based theory of plate climatology.
There is also one aspect of this new research that does not fit into PCT, inasmuch that the researchers explanation of what causes the episodic “on/off” nature of these giant plate boundary rift systems is incorrect.
They hypothesize glacial melt water raises sea level, which results in a taller column of seawater. The taller column of water exerts increased downward pressure on the rift systems, thereby turning them “off” and decreasing rift activity. Conversely, when ice caps reform, the sea level drops, downward pressure decreases, and the rift activity is turned back “on.”
There are several problems with this proposed sea-level induced on/off rift activity mechanism:
- ) Downward pressure is insufficient: When the ice caps melt sea level would raise approximately 200-250 feet, as stated by current climate scientists. So let’s use 250 feet, the maximum. This equates to 110 psi (pounds per square inch) of downward pressure, because sea water exerts 14.5 psi per 33 feet. It seems very unlikely that a 110 psi change in pressure could affect world class rift systems that have the force to move entire continents 2-3 centimeters per year. Stated another way, the average depth of most ocean rift systems, for example the Mid Atlantic rift, is 7,000 feet. Pressure at 7,000 feet is 3,075 psi. The additional 250 feet of sea water from ice cap melting would be a 3.5% increase in pressure. It’s very difficult to imagine that a 3.5% increase alone would alter rift system mechanics.
- ) Rift systems move sideways: The next big problem is that rift system faulting moves rock layers sideways, so downward pressure from increased water depth would have minimal effect on the sideways movement of rifts. Actually a case can be made that downward pressure might act to increase sideways rift movement.
- ) Upward seawater and gas expulsion: Expulsion of water and gases from the ocean rift system hydrothermal vents exerts an upward force, which would act to diminish the affect of the downward sea level rise induced force.
- ) Rock layer mechanics: The basic problem here is that rock layer mechanics are extremely complicated and not predictable. Many geologists have dedicated their entire lives to trying to accurately predict when and how pressured rock layers open and close. To date no one has figured it out. Here is just a one example. Let’s assume for a moment that the increased pressure does push down on rock layers. The mechanics would work like this in a “bowl shaped” ocean basin. As the top of a rock layer is pushed down it would compress together. The result would be to close / tighten the rock. Heat flow would theoretically turn “off.” However the bottom of the same rock layer would expand, which would act to open and loosen the bottom of the layer. Heat would theoretically be turned “on.” Now throw in varying layer angles and rock density variations and you can easily see why it is tough to predict how rock layers will react to simple downward pressure.
- ) Complex word class rift systems: Finally, and most importantly, these are 5,000- to 7,000-mile-long geologically complex rift systems; active volcanoes, super-active hydrothermal vents, faults, cross-faults, varying rock layer densities, varying rock layer thicknesses, varying fault spreading rates, etc. To effectively turn these types of systems on and off uniformly and in a reasonably small time frame a very large force is needed. It is difficult to believe that a mere 110 psi increase in downward force would get this massive job done.
A much more logical explanation of what turns rift system activity on and off is natural variation in the Earth’s very powerful and extensive upper mantle convective system (see image), which “carries heat from the interior of the Earth to the surface.”
This power is episodically released at tectonic plate boundaries and rift systems, which warm our oceans, warm the atmosphere, and melt polar ice caps. The result? Geological rift systems “rock” our climate.
James Edward Kamis is a Geologist and AAPG member of 40 years and has always been fascinated by the connection between Geology and Climate. Years of research and observation have convinced him that the Earth’s heat flow engine, which drives the outer crustal plates, is also an important driver of our climate. Please use the Contact Us page to reach James.