Earth's core is cooling at rates faster than previously thought, which could speed the planet's inevitable march toward uninhabitability millions or billions of years from now, researchers said this week.
In summary, the Earth's core is cooling very, very slowly; some of it has solidified, but it will take many billions of years for the rest to follow suit.
When the Earth's core cools and solidifies, researchers say, that magnetic field will disappear and the planet will become similar to Mars, “affecting every planetary process as we know it,” TWC India's Mrigakshi Dixit reported.
While that sounds pretty alarming, some estimates for the cooling of Earth's core see it taking tens of billions of years, or as much as 91 billion years. That is a very long time, and in fact, the Sun will likely burn out long before the core — in around 5 billion years.
Scientists estimate it would take about 91 billion years for the core to completely solidify—but the sun will burn out in a fraction of that time (about 5 billion years).
Unfortunately, the magnetic field disappeared, which caused the planet's atmosphere to be stripped over time to the point that it became extremely thin (as it is today). Scientists attribute this to Mars' lower mass and density (compared to Earth) which resulted in its interior cooling more rapidly.
That led to the conclusion that the temperature of the center of the Earth is about 6000 degrees Celsius - a temperature about 9% higher than what exists on the surface of the Sun.
Scientists think that when that happens, Earth might be a bit like Mars, with a very thin atmosphere and no more volcanoes or earthquakes. Then it would be very difficult for life to survive – but that won't be a problem for several billions of years. Right now, the Earth's core is not entirely molten.
Thanks to data from rovers and other spacecraft, we know that the Red Planet once fairly sloshed with water—with dry deltas, riverbeds, and sea basins stamped into its surface. But 4 billion years ago, the Martian core cooled, shutting down the dynamo that sustained its magnetic field.
For all this, however, Marone says, the vast majority of the heat in Earth's interior—up to 90 percent—is fueled by the decaying of radioactive isotopes like Potassium 40, Uranium 238, 235, and Thorium 232 contained within the mantle. These isotopes radiate heat as they shed excess energy and move toward stability.
There are three main sources of heat in the deep earth: (1) heat from when the planet formed and accreted, which has not yet been lost; (2) frictional heating, caused by denser core material sinking to the center of the planet; and (3) heat from the decay of radioactive elements.
The Martian mantle between the crust and core is roughly half as thick as Earth's. And the Martian core is on the high side of what scientists anticipated, although smaller than the core of our own nearly twice-as-big planet. These new studies confirm that the Martian core is molten.
In a word, no. The center of the Earth is roughly 3,959 miles (6,371 km) down. The deepest hole that was ever drilled was the Kola Superdeep Borehole, at 7.6 miles (12.26 km) deep. That's 0.19% of the way to the center of the Earth.
Earth has experienced cold periods (or “ice ages”) and warm periods (“interglacials”) on roughly 100,000-year cycles for at least the last 1 million years. The last of these ices ended around 20,000 years ago.
Murakami and his colleagues found that the thermal conductivity of bridgmanite was 1.5 times higher than expected. "The heat transfer from the core would go more efficiently than previously thought, which ultimately leads to the cooling of the core more rapidly than expected," Murakami said.
Solar geoengineering: Too much risk
Scientists know that aerosol particles can temporarily cool the earth's surface. Fine ash from the 1991 eruption of Mount Pinatubo — the largest volcanic eruption in the last 100 years — lowered global temperatures by 0.5 degrees Celsius (0.9°F) for almost two years.
Solar winds may have led to Mars losing its atmosphere, according to a computer simulation study which confirms the long held belief that planets need a protective magnetic field to block such harmful radiations in order to sustain life.
According to their analysis, changing the amount of carbon dioxide in the atmosphere didn't alter Mars' fate, but losing non-CO2 greenhouse gases likely caused Mars to dry out.
Mercury. Mercury is a dead planet and the most heavily cratered object in the solar system. It is a world of black starry skies, gray craters, no moon and not enough gravity to hold an atmosphere. Without an atmosphere, Mercury is a silent world without any sound.
Geothermal energy is the heat produced deep in the Earth's core. Geothermal energy is a clean, renewable resource that can be harnessed for use as heat and electricity. Geothermal energy is heat that is generated within the Earth.
Radioactive decay will not help the magnetic field, though, as the elements are situated in the mantle and crust. Obviously, reheating the core is going to be impossible.
At the Equator, the earth's rotational motion is at its fastest, about a thousand miles an hour. If that motion suddenly stopped, the momentum would send things flying eastward. Moving rocks and oceans would trigger earthquakes and tsunamis. The still-moving atmosphere would scour landscapes.
Earth Science FAQs - Volcanoes
The Earth's mantle, on which the crust is lying on, is not made of liquid magma. It is not even made of magma. The Earth's mantle is mostly made of solid rock.
In the core, the process of nuclear fusion creates temperatures of approximately 27,000,000° F. A temperature of 27 million degrees Fahrenheit is more than 12,000 times hotter than the hottest lava on Earth! If the core is the hottest part of the sun, what's the coolest part?
The dead star at the center of the Red Spider Nebula has a surface temperature of 250,000 degrees F, which is 25 times the temperature of the Sun's surface. This white dwarf may, indeed, be the hottest object in the universe.