THE SECRET that drives the Earth's habitability lies some 2,000-6,000 kilometres below our feet in the core of the planet. We know that the innermost layer of the Earth is slowly turning solid, and as it does, it radiates heat that generates a magnetic field which rises to surround and protect the planet. But all our understandings on the core are based on just hypothesis; there is so much about the Earth's heart that eludes us.
In fact, the world has seen more success in space than in understanding its own planet. US space agency NASA's Voyager 1 spacecraft, launched in 1977, has travelled 23 billion km from the Earth. In contrast, the deepest hole drilled into the planet's surface is just 12.2 km (more on this later). What makes it difficult to conduct physical studies of the core is the unforgiving interiors of the Earth. Human bones could turn into dust at depths of 200 km. The base of the crust has a temperature of around 1,000°C, the bottom of the mantle is 3,000°C and the core is about 6,000°C. The pressure, too, could kill. Studies show it can range from 24-136 gigapascals (1 gigapascal or GPa is 1 billion pascals) in the lower mantle to 135-330 GPa in the outer core and 330-365 GPa in the inner core. Humans can only withstand up to a few thousand KPa (1 kilopascal or KPa is 0.012 GPa).
Therefore, any study that tries to throw some light on the functioning of the core is subject to abject scrutiny. Two such studies, published early this year, have triggered debate and discourse among scientists, while highlighting that we do not yet have the technological resources to reach the deep Earth and gain more concrete insights.
Denne historien er fra April 01, 2023-utgaven av Down To Earth.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
Allerede abonnent ? Logg på
Denne historien er fra April 01, 2023-utgaven av Down To Earth.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
Allerede abonnent? Logg på
A SPRIG TO CARE FOR
Punarnava, a perennial herb, is easy to grow and has huge health benefits
DIGGING A DISASTER
Soapstone mining near Dabti Vijaypur village has caused many residents to migrate.
REVIEW THE TREATMENT
Several faecal sludge treatment plants in Uttar Pradesh suffer from design flaws that make the treatment process both expensive and inefficient
MAKE STEEL SUSTAINABLE
As India works to double its GDP by 2030, its steel industry must balance growth with sustainability. By embracing policies like the Steel Scrap Recycling Policy 2019 and adopting green technologies, India is paving the way for a more sustainable future in steel production
Can ANRF pull off the impossible for India?
Anusandhan National Research Foundation is expected to reorient India's innovation goals but funding issues, old mindsets remain a drag
TROUBLED WOODS
Forests are a great bulwark against climate change. But this is fast changing. AKSHIT SANGOMLA travels through some of the pristine patches of the Western Ghats to explore how natural disturbances triggered by global warming now threaten the forest health
BLINDING GLOW
The science is clear: increased illumination has damaging consequences for the health of humans, animals and plants. It’s time governments introduced policies to protect the natural darkness and improved the quality of outdoor lighting.
GROUND REALITY
What happens when the soil loses the ability to grow healthy, high-yield crops on its own?
GM POLICY MUST BE FARMER CENTRIC
On July 23, the Supreme Court of India directed the Union government to develop a national policy on genetically modified (GM) crops for research, cultivation, trade and commerce through public consultation.
Vinchurni's Gandhi
A 96-year-old farmer transforms barren land into a thriving forest in drought-prone region of Satara