Paragraph 1
We know
about the centre of Earth. Geologists believed our
had just one core – a hot mass of
rock and gas surrounded by a rock mantle. The mantle is a
between the earth's
and core. The core is 2,900 kilometres below Earth's surface. It has a
of around 3,485 kilometres. Scientists have found that there may be a
core. Geophysicist Sunyoung Park analyzed
from a 560-km-deep earthquake. Her
showed the possibility of a second core. It consists of a
of fluid rock at the bottom of the mantle.
