The morphological evidence shown on the World Ocean Floor map should be sufficient to convince skeptics that the Earth has expanded by an extraordinary amount in the past ~200 Ma—the entire surface area now covered by the world’s oceans. Indeed, in terms of surface area, the oceans that now cover ~71% of the planet's surface (~361,637,000 km²) did not exist when Pangaea began to break up ~200 Ma. This means that the remaining ~29% of the Earth's surface (~148,500,000 km²) once constituted the entire surface area of the planet when its diameter was approximately 55-60% of today's equatorial diameter of 12,756.254 km (7926.75 miles).
This does not mean there were no bodies of water on the planet at that moment in geologic time, because at least two (perhaps more) large but shallow bodies of water, known as "epicontinental seas," are known to have existed at about that time. The best known of these was the Tethys Sea that covered much of Eurasia, and the other covered much of the continental United States from the Rocky Mountains to the Appalachians (before either orogen was formed).
Huge salt and other mineral deposits found in many areas of the world are further evidence of lakes or seas that once existed at various periods of geologic time long before today's oceans were formed. Such deposits are further proof that we know very little about Earth's early history because so much is now hidden beneath the many layers of earth that have accreted from outer space over many millennia of geologic time.
Highways cut through mountains along Interstate Highway 40 near Nashville, in Central and East Tennessee, and Interstate Highway 75 into Kentucky exposed large sedimentary limestone deposits that confirm the earlier existence of an inland sea in this area. (The author speculates that the Grand Canyon may have been formed by runoff from this epicontinental sea when the ocean basins were first created.)
If the planet had no major oceans (the hydrosphere) at the end of the Triassic ~200 Ma, then where did all of today's ocean water come from? This is a profound question with a simple answer: The hydrosphere has been gradually outgassed from the core of the Earth via the terrestrial volcanoes and LUVs as a byproduct of core melting, which distills H²O, minerals, and other gases from the solid material that formed the planet's original nucleus. Earth's atmospheric envelope was simultaneously outgassed as a part of this same process, and the atmosphere grows thicker with each passing day.
The midocean LUVs vigorously extrude new basaltic seafloor and virgin new water via "black smoker" vents, plus an unknown, but prodigious, amount of other gases, minerals and heat as byproducts of the expansion process.
Earth's current volume of surface water, according to the nebular hypothesis and plate tectonics, is believed to have always existed since the planet originally coalesced ~4.5-4.6 Ga, but the evidence that Pangaea constituted the entire surface of the planet at the end of the Triassic makes it clear that this is not true.
Terrestrial volcanoes were the sole source of terrestrial water in archaean times, when there were no oceans and surface water was confined to lakes and epicontinental seas. Inception of the midocean ridges at the end of the Triassic became the primary source of water and magmatic expansion of the ocean basins
The LUVs are now the single greatest source of new water filling the expanding ocean basins, so research is needed to determine whether new ocean basin growth is keeping up with the increasing volume of new water. Some researchers suggest that shorelines have receded substantially in recent centuries, but that may depend on other factors—the city of Venice (which is sinking) being a case in point.
Magma extruded via terrestrial volcanoes quickly cools upon contact with cooler air, but not before it has flowed over and changed the surrounding landscape. However, when hot magma extruded via the LUVs contacts cold seawater it quickly hardens into new basaltic seafloor that continuously increases the total surface area of the ocean basins. Because the continents literally float in isostatic equilibrium on the core's sea of molten magma, they can be slowly pushed apart by this intrusive volcanic seafloor growth process (vide the ~4,000 km distance now separating the Americas from Europe and Africa and the ~10,000 km separating Australia from South America.)
RIDGES AS A SOURCE OF GLOBAL WARMING?
searching for the causes of global warming may have overlooked a hidden
factor----massive volumes of heat flowing from the midocean ridges that almost completely encircle the
Earth. The ridges are hidden underwater and unseen except
for the short stretch that runs through Iceland as part of the ongoing
volcanic process that created the island and continues to modify its
surface features on a daily basis.
heat flux from the midocean ridges could prove to be the primary heat
source causing global warming because they are a single and virtually
continuous worldwide "linear underwater volcano" (LUV)
extruding superheated molten magma (molten rock) and byproducts
(chemicals, minerals and gases, plus virgin new H²O) of the core
melting process that coagulate or precipitate out to form new basaltic seafloor when
they meet extremely cold seawater at the ocean floor.
they have not already done so, the world's meteorologists, marine
scientists and volcanologists should investigate the heat flux emanating
from these worldwide midocean ridges to determine whether the flux is
the primary factor in global warming, just another contributory factor,
or of little consequence. Unknown
to most people, the most active volcanism on the planet is concentrated
in a short section of the midocean ridge just south of the equator along
the East Pacific Rise (EPR)--and directly below the area where El Niños spawn in heated
surface waters. Is this
mere coincidence, or cause and effect?
of new basaltic ocean seafloor along this short hyperactive stretch of
the EPR has been measured at ~15-16 cm/yr, four times the growth rate
along other sections of the EPR or the worldwide LUV system. The total volcanic heat flux from this source is
undoubtedly massive, but it is not known whether the rate and total
volume of heat has ever been calculated for the entire Earth.
previous consideration of this heat source was dismissed because of
alternating El Niños and La Niñas (the cold water version of El Niños),
another review of the evidence may be in order because the periodicity
of these phenomena may be explained by the fact that volcanic activity
fluctuates unpredictably and is seldom sustained over long periods of
time, permitting the ocean waters to cool and La Niñas to develop
during periods of quiescent EPR volcanism.
reports of progressively higher annual temperatures worldwide and
shrinking ice packs in the Arctic and Antarctic may be precursors of
greater trouble ahead if the planet grows significantly warmer, as it
surely will do as a result of global expansion.
Possibly enhanced by the El Niño effect, global warming and its effects on the planet took center stage in 1997, 1998, and 1999 as worldwide reports of unusually severe hurricanes, tornadoes, storms, heavy rains, disastrous floods and heat waves captured media attention. Automobile and factory emissions, ozone depletion and greenhouse effects of a polluted atmosphere, plus other potential causative factors, have been studied extensively but there is no consensus as to what causes global warming.
though it does not pose an immediate
threat to life, global warming is recognized as a long-term threat to
plant and animal life and the planetary environment that sustains all
How will Mankind cope with a continued increase in heat that will
undoubtedly result from expansion of the Earth?
How will Mankind cope with a continued increase in heat that will undoubtedly result from expansion of the Earth?
© 1999, St. Clair Enterprises (Page last updated 26 Sep. 1999)