Earth's interior cycles contributor to long-term sea-level and climate change, scientists conclude

Mar 18, 2013
Earth
German researchers at the University of Bonn said that the world is smaller than first thought.

Ancient rises in sea levels and global warming are partially attributable to cyclical activity below the earth's surface, researchers from New York University and Ottawa's Carleton University have concluded in an analysis of geological studies.

However, the article's authors, NYU's Michael Rampino and Carleton University's Andreas Prokoph, note that changes spurred by the earth's interior are gradual, taking place in periods ranging from 60 million to 140 million years—far less rapidly than those brought on by human activity.

Their analysis appears in Eos, a newspaper published by the .

Rampino and Prokoph's analysis considers long-term fluctuations in , diversity of , and sea level changes, aiming to identify a unifying cause for these changes. While much scientific study has centered on phenomena above the earth's crust, less attention has historically been paid to changes deep inside our planet.

In recent years, however, researchers have examined the upwelling of —the rising up of heated rocks from earth's mantle that reach the earth's surface. These plumes have a notable impact on one geologic occurrence: the eruption of large igneous provinces (LIPs), which are large accumulation of rocks formed from congealed lava.

In their analysis of recent scientific findings, Rampino and Prokoph observe that mantle plumes coincide with cyclical surface changes, suggesting that the plumes themselves may be cyclical in nature. For example, Prokoph's previous research has found that many geological changes had cycles of 60 and 140 million years and suggested the cyclical uprising of these plumes to form hotspots—areas on the earth's surface where volcanic activity has endured.

More broadly, the researchers write, mantle plumes push up against the earth crust, shifting water to continents, thereby producing rise, and precipitating volcanic activity, which produces additional CO2, leading to a warmer climate.

"Mantle plumes appear to show regular cycles," Rampino explained. "So what's remarkable is there is a strong indication of a connection between changes on the earth's surface—such as and rising sea levels—and what's occurring deep inside the earth. This suggests a fascinating and powerful union between below-surface geological events and changes in our climate."

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Lino235
2 / 5 (12) Mar 18, 2013
Vendicar: Isn't this exactly what I've claimed before? How do you respond?
Caliban
4.2 / 5 (10) Mar 18, 2013
Vendicar: Isn't this exactly what I've claimed before? How do you respond?


@Lino,

Note the time scale they specify. Also note that what they are talking about are MASSIVE vulcanism on the scale of supervolcanic eruptions and Siberian- and Deccan- Traps, or even the massive flow basalts of the western US.

In between the large-scale catastrophic events, the sea-level change and climate warming are just background noise.

Try to develop a more thorough understanding of things before you go about beating your chest that you've proven some point --because you haven't-- in terms of of disproving AGW.

Lino235
1.7 / 5 (12) Mar 18, 2013
Caliban:

Before you start beating your chest, are you going to maintain that there is no scale in between "large-scale catastrophic events" and normal thermal cycles in earth's atmosphere?

The fact that we're dealing with a "large-scale" event makes my point: that mantle can, and does, intrude upwards over geologic time, and that upward intrusion can cover vast areas of the earth's crust. Hence, where we "see smoke", we see mantle encroaching towards the upper crust. Over large swaths of crust, small, incremental intrusions---nothing on the scale of the catastrophic---can cause water temperatures on the sea floor to rise slightly, and cause a slight increase in CO2 production as well.

This is a much more plausible explanation than AGW. Why? Because the 'warming' we've seen, we've seen start in the 1830's and 40's. Nothing remotely close to today's CO2 production was taking place at the time. Hence, an unadulterated science requires a cause of this increase outside of AGW.
Caliban
4.4 / 5 (7) Mar 19, 2013
The fact that we're dealing with a "large-scale" event makes my point: [[that mantle can, and does, intrude upwards over geologic time, and that upward intrusion can cover vast areas of the earth's crust. Hence, where we "see smoke", we see mantle encroaching towards the upper crust. Over large swaths of crust, small, incremental intrusions---nothing on the scale of the catastrophic---can cause water temperatures on the sea floor to rise slightly, and cause a slight increase in CO2 production as well.]]


The fact is that this crap you wrote that I bracketed out of the quoted section of your cvomment is utter hogwash, and is clear evidence that you haven't even the foggiest of notions regarding geodynamics and vulcanism.

There ARE NO current "mantle intrusions" onto the crust anywhere, with the exception of a VERY FEW active volcanoes around the world(whose emissions are negligible when averaged out year-to-year) and the mid-oceanic ridges, which remain stable over megayears.

Claudius
1 / 5 (5) Mar 19, 2013

There ARE NO current "mantle intrusions" onto the crust anywhere, with the exception of a VERY FEW active volcanoes around the world


"Supervolcanoes can occur when magma in the mantle rises into the crust from a hotspot but is unable to break through the crust. Pressure builds in a large and growing magma pool until the crust is unable to contain the pressure. They can also form at convergent plate boundaries (for example, Toba) and continental hotspot locations (for example, the Yellowstone Caldera)."

"Although there are only a handful of Quaternary supervolcanoes, supervolcanic eruptions typically cover huge areas with lava and volcanic ash and cause a long-lasting change to weather (such as the triggering of a small ice age) sufficient to threaten species with extinction." - Wikipedia
Caliban
5 / 5 (5) Mar 19, 2013

There ARE NO current "mantle intrusions" onto the crust anywhere, with the exception of a VERY FEW active volcanoes around the world


"Supervolcanoes can occur when magma in the mantle rises into the crust from a hotspot but is unable to break through the crust. Pressure builds in a large and growing magma pool until the crust is unable to contain the pressure. They can also form at convergent plate boundaries (for example, Toba) and continental hotspot locations (for example, the Yellowstone Caldera)."

"Although there are only a handful of Quaternary supervolcanoes, supervolcanic eruptions typically cover huge areas with lava and volcanic ash and cause a long-lasting change to weather (such as the triggering of a small ice age) sufficient to threaten species with extinction." - Wikipedia


That's nice, Claudius -but what's your point? Even during active filling of these magma chambers, the thermal and CO2 contributions of SVs is negligible, until eruption.