The definition of a scientist is a person who studies or practises any of the sciences. Scientists find out about the unknown and the known. They try to find out why things work and why they don’t work. There are hundreds of different types of scientists. For example, astronomers study space, botanists study plants and entomologists study insects.
Seismologists study earthquakes
Scientists who study earthquakes are called seismologists. Seismologists know quite a bit about the inside of the Earth. They can’t know everything because it’s 6,300 km to the centre of the Earth and the longest drill we have has only drilled to 12.6 km. Because scientists cannot visit or see what is happening far under the ground, they use special instruments called seismographs to help them work out what is happening inside the Earth.
Seismographs measure waves that travel under the ground. We cannot see these waves, but they are sometimes felt as earthquakes. (We can see waves in the water, but there are many types of waves we cannot see – light waves, sound waves and seismic waves.) These underground waves help scientists figure out what makes up the Earth and how it works.
Dr Laura Wallace works at GNS Science. She studies Earth movements and thinks New Zealand is one of the best places in the world to study earthquakes.
Volcanologists study volcanoes
Some scientists know a lot about volcanoes. They are called volcanologists. Volcanologists study volcanoes that erupted thousands of years ago as well as volcanoes that are active right now. New Zealand scientists study both kinds of volcanoes.
Dr Phil Shane of the University of Auckland looks at rocks for clues about when old volcanoes erupted. He uses a special drill to dig up rocks from several metres underground. The colours and textures of the rocks show him how often volcanoes around New Zealand have erupted.
Nature of science
Scientists who study earthquakes and volcanoes know quite a bit about why they happen, but there is still a lot they do not know. Scientific knowledge is said to be tentative – theories and laws may change with new evidence.
Keeping our buildings safe
Another group of scientists work to protect us from damage caused by earthquakes and volcanic eruptions. Seismic engineers work on new ways to keep buildings like hospitals and structures like bridges safe when the ground shakes. Many of these buildings were shaken in Wellington and Christchurch earthquakes but were not damaged.