How do earthquakes geologists understand earth’s interior? during an earthquake, geologists use a machine called a seismograph/drilling rig/magnetometer to study seismic waves. p waves can pass through both solid and molten rock, but s waves can pass only through molten/solid/ tarry rock.

During an earthquake, geologists use a machine called a SEISMOGRAPH to study seismic waves.

P waves can pass through both solid and molten rock, but S waves can pass only through SOLID rock.

Date:
February 3, 2010
Source:
Wiley-Blackwell
Summary:
For 80 years it has been accepted that early life began in a "primordial soup" of organic molecules before evolving out of the oceans millions of years later. Today the "soup" theory has been overturned in a pioneering article which claims it was the Earth's chemical energy, from hydrothermal vents on the ocean floor, which kick-started early life.