![]() ![]() The inner core's outer shell and its newly confirmed innermost sphere both are hot enough to be molten but are a solid iron-nickel alloy because the incredible pressure at the center of the Earth renders it a solid state. Our study becomes possible thanks to the unprecedented expansion of the global seismic networks, particularly the dense networks in the contiguous U.S., the Alaskan peninsula and over the European Alps," Pham added. "We analyzed digital records of ground motion, known as seismograms, from large earthquakes in the last decade. ![]() ![]() "We may know more about the surface of other distant celestial bodies than the deep interior of our planet," said observational seismologist Thanh-Son Pham of the Australian National University in Canberra, lead author of the study published in the journal Nature Communications. The new research studied waves from 200 quakes with magnitudes above 6.0 ricocheting like ping pong balls up to five times within the planet. Until now, scientists were able to detect these waves bouncing up to twice, from one side of Earth to the other and then back. The increasing sophistication of seismic monitoring enabled this to be confirmed.Įarthquakes unleash seismic waves that travel through the planet and can reveal the contours of its interior structure based on the changing shape of the waves. Scientists in 2002 proposed that lurking within this inner core was an innermost section separate from the rest, akin to a Russian Matryoshka nesting doll. This metallic inner core, about 1,500 miles (2,440) wide, was discovered in the 1930s, also based on seismic waves traveling through Earth. The planet's internal structure comprises four layers: a rocky crust on the outside, then a rocky mantle, an outer core made of magma and a solid inner core. Researchers on Tuesday said an intensive study of Earth's deep interior, based on the behavior of seismic waves from large earthquakes, confirmed the existence of a distinct structure inside our planet's inner core - a wickedly hot innermost solid ball of iron and nickel about 800 miles (1,350 km) wide.Įarth's diameter is about 7,900 miles (12,750 km). The actual center of the Earth is nothing like this fanciful depiction - and in some ways is even more dramatic. WASHINGTON, Feb 21 (Reuters) - In Jules Verne's classic 1864 novel "Journey to the Center of the Earth," adventurers descend through an Icelandic volcano into a vast underground world populated by prehistoric creatures as they explore our planet's interior. ![]()
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