Scientists probe ’mystery of the Moho’

Prof Chris MacLeod leads team on a cruise to the Indian Ocean to drill into the Earth's interior. An international team of scientists, co-led by Professor Chris MacLeod from the School of Earth and Ocean Sciences , will set sail for a remote location in the Indian Ocean as part of an expedition to test a 100-year-old theory that currently underpins our understanding of the Earth's structure. Professor MacLeod and his team, from the International Ocean Discovery Program (IODP), will set sail aboard the JOIDES Resolution research vessel and drill through the Earth's crust at a target site on the South West Indian Ridge submarine mountain chain. They will be looking for evidence that will overturn currently accepted theories describing the nature of the Earth's outermost layers, and could have profound implications for our understanding of the Earth's crust and the extent of life on the planet. The Earth's interior is layered, like an onion, with four distinct sections: the crust; the mantle; the inner core; and the outer core. Between the outermost layer - the crust - and the mantle, a boundary exists, called the Moho. The Moho is named after the Croatian seismologist Andrija Mohorovi'i? who first noticed in 1909 that seismic waves from earthquakes changed speed about 50 kilometres below the planet's surface.