When an earthquake occurs, the shockwaves of released energy that shake the Earth and temporarily turn soft deposits, such as clay, into jelly (liquefaction) are called seismic waves, from the ...
Relative dating is used to arrange geological events, and the rocks they leave behind, in a sequence. The method of reading the order is called stratigraphy (layers of rock are called strata) ...
Geologists often need to know the age of material that they find. They use absolute dating methods, sometimes called numerical dating, to give rocks an actual date, or date range, in numbers of ...
Use this interactive to work out the relative ages of some rock layers from youngest to oldest. Drag and drop the text labels onto the diagram. Go here to find out more about how to use this ...
Rocks are not all the same. Some are heavy, some are light. Others are dark, while some can be almost pure white. Even igneous rocks that are all formed from magma in the Earth’s mantle can look ...
Calcium carbonate is the principal mineral component of limestone. Its chemical and physical properties lie behind the modern-day uses of limestone as well as the unique limestone landscapes of ...
The Earth rumbles and a hiss of steam issues from the top of Mt Ruapehu. Are these two events related? Is the earthquake caused by the volcano? Or is the steam caused by the earthquake? Tectonic ...
A mineral is an element or chemical compound that is normally crystalline and that has been formed as a result of geological processes. Examples include quartz, feldspar minerals, calcite, sulfur ...
There are many different types of volcanoes around New Zealand. This interactive map shows where the major volcanoes are, the types of volcanoes and various facts such as when they last erupted ...
Base isolation is a technique developed to prevent or minimise damage to buildings during an earthquake. It has been used in New Zealand, as well as in India, Japan, Italy and the USA. A ...
Pure lime, or quicklime, is calcium oxide. Its ease of manufacture and chemical properties make it an important industrial chemical. Lime has a long history dating from the earliest of times. Its ...
We can blame plate tectonics for many catastrophes over time – earthquakes, volcanoes, geothermal activity, tsunamis and landslides – while people living on mountain ranges or small islands can ...
Most sedimentary rocks are laid down in flat, horizontal layers. These can later tilt and fold due to tectonic activity, and river cuttings can cause gaps among the layers. Geologists are able to ...
What is happening inside this 12,700 km diameter ball we call the Earth? Some of the Earth’s internal architecture is an 'educated guess' (mainly from seismology), because the longest drill we ...
The Earth is an enormous place. There is so much that we don’t yet know about what happens on the surface of the Earth, so how could we possibly know about what happens deep down below the Earth’ ...
The Earth is an active planet. Earthquakes shake and volcanoes erupt. Sections of the crust are on the move. Mountains push up and wear down. These and many other processes contribute to the rock ...
Everyone knows what a volcano looks like – isn’t it a steep-sided cone with wisps of ash coming from the top, just like Rangitoto, White Island, Mt Ngāuruhoe or Mt Ruapehu? But what about small ...
The city of Auckland is built on a volcanic field. There are 50 volcanoes within an area of 1,000 square kilometres, forming the hills, lakes and basins of the city. Rangitoto Island was formed ...
Estuaries have a life cycle. They form, they age as they infill with sediment and they transform to other environments, such as freshwater marshes. They are fragile habitats vulnerable to time ...
The Earth’s continents have not always been where they are at present. If you look at a map of the world, you might notice what Alfred Wegener noticed – that the continents look as if they could ...
The calcium carbonate content of limestone rocks has been used from the earliest civilisations, dating back to 14,000 BCE, to its extensive use in modern times. It is a valuable resource that ...
In the South Island of New Zealand, the boundary between the Australian and Pacific tectonic plates can be seen on land. This is unlike the North Island boundary, where a subduction zone is under ...
Limestone is a very common sedimentary rock consisting of more than 50% calcium carbonate. Although it occurs in many different forms, its origins can be traced back to either chemical or ...
Liquefaction is a process that temporarily turns firm ground into a liquid. During the Canterbury earthquakes of September 2010 and February 2011, liquefaction caused silt and fine sand to boil ...
