Levels: During superplume activity, sea levels rise.
This lessens the total amount of landmass making the world have
more oceans. The sea levels
rise partly because the temperature increases due to the greenhouse
effect melting the polar ice caps.
Formation of Oceanic Crust:
Superplume activity causes plate tectonic to go into full motion.
Plate spreading rates increase tremendously, much of
which is in the form of oceanic crust. You may have noticed
much of the earth's images on this website look a little differently.
The earth changes by the
movement of the continents from plate tectonics.
Magnetic Reversals: Magnetic
reversals usually occur a few times every million years, but
when superplumes activity occurs magnetic reversals stop
for the millions of years they are active. Notice the below
left chart: During the Cretaceous no magnetic reversals occured.
This is some of the evidence
that superplumes are active. The image to the right shows a
scientist's view of how magnetic reversals look when in the
process of switching.
15: Temperature curve
for past 150 million years ___Image
16: This image shows
what a magnetic reversal may look like when in the process
of the Past Geologic Process: When did they occur?
Cretaceous Superplume event:
Scientist have the most information to back up a hypothesis
for a superplume event during the Cretaceous 120-80
million years ago in the Pacific basin. During this period oceanic
crust production increased by 50-75%. Ocean levels were higher
than present day levels.
During this period magnetic reversals also stopped for 41 million
years.CO2 pressure levels were six to
eight times higher than they are today creating
a "super-greenhouse" effect. An increased production
of black shale occured primarilt because of the increase in
organic productivity and poor basin
of the world’s known oil was formed in Albian to Turonian
stages (112 to 88 million years ago), a period during the Cretaceous.
this period the Hess Rise, Line Islands, and the Manihiki Plateaus
were all formed or present near the pacific superplume.
17: Late-Creataceous Earth. Notice how the sea levels are high
and little land mass is visible.
Above shows the climate of the late-Cretaceous. Notice most
of the Earth consists of either arid, warm temperate, or tropical
climates. Only the far north and south are cool temperates.
More of a controversy exists over the existence of the
Pennsylvania/Permian superplume.Some evidence does,
however, exists that supports the existence of this superplume.
It is believed that magnetism was reversed during this period.
explains the climate of this time period of swampy, tropical,
wet conditions in the northern hemisphere, and the glaciation
in the southern hemisphere
or Gondwanaland. The magnetic reversal may play a role in the
warmer climates in the north and the cooler climates in the
south by the magnetic poles
being switched. Sea levels and gas accumulations both rose during
this period. Much of the coal that we mine today in Northern
Russia, and China formed during the Permian. Magnetic reversals
did not occur during the 75 million years the Pennsylvanian/Permian
superplume was active.
19: Above shows the late-Permain earth. Notice how much the
sea levels have risen and how little land mass is visible.
Locations of Superplumes today,
past and present:
Much of the past superplume activity is theorized from from
looking at fossil and rock (basaltic lavas especially) records.
hypothesized that past plates like Farallan Plate, à
Hess Rise, Line Islands, and Manihiki Plateau all formed at
the Pacific/Farallan boundary
during superplume activity. Some of these occurred or were present
during the Cretaceous period of 90-150 million years ago and
of the Polynesian superswell. The presence of the superswell
can still be visible when monitoring the magma activity inside
the Earth. Some
scientists believe that a superswell today feeds many of the
volcanic activity in the Pacific basin.
20: Above shows much of the volcanic activity today. When looking
at the "Ring of Fire" notice how much of the volcanic
around the pacific ocean. Some scientists have hypothesized
that much of this activity is fed from the superswell below.
Image 21 and Image
When looking at the
images above show a superswell in the middle of the Pacific.
Both these images show the vocanic activity at certain depths
the Earth. Notice on the images that there is definite activity
in the Pacific and Africa.
- Latest pulse of Earth; evidence for a Mid-Cretaceous super
plume, Larson, R. L. In: Geology, June 1991, Vol. 19, Issue
- Geological consequences of superplumes, Larson, Roger L. In:
Geology, October 1991, Vol. 19, Issue 10, pp.963-966
- Geochemical evidence for a Mid-Cretaceous superplume, Tatsumi,
Yoshiyuki In: Geology, February 1998, Vol. 26, Issue 2, pp.151-154
- The Mid-Cretaceous superplume episode, Larson, Roger L. In:
Scientific American, February 1995, Vol. 272, Issue 2, pp.82-86
- Superplumes from the core-mantle boundary to the lithosphere;
implications for heat flux, Romanowicz, Barbara In: Science,
April 19, 2002,
Vol. 296, Issue 5567, pp.513-516
- Impact dust not the cause of the Cretaceous-Tertiary
mass extinction, Pope, Kevin O. In: Geology, February 2002,
Vol. 30, Issue 2, pp.99-102
-Catastrophic events in the mantle and episodic
growth of continents, Condie, Kent C. In: Abstracts with Programs
- Geological Society
of America, 1998, Vol. 30, Issue 7, pp.345-346
- Power Point: Superplume Project:Towards
a new view of whole Earth dynamics
Click on the Image for the link
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David Wainwright Peake III
Creation/last revision date: 07.February. 2003 / 08.April.2003