Subject: Geological Engineering Design

Hot Spring

A hot spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow bodies of magma (molten rock) or by circulation through faults to hot rock deep in the Earth's crust. In either case, the ultimate source of the heat is radioactive decay of naturally occurring radioactive elements in the Earth's mantle, the layer beneath the crust.

Landslide

A landslide is defined as the movement of a mass of rock, debris, or earth down a slope. Landslides are a type of "mass wasting," which denotes any down-slope movement of soil and rock under the direct influence of gravity. The term "landslide" encompasses five modes of slope movement: falls, topples, slides, spreads, and flows. These are further subdivided by the type of geologic material (bedrock, debris, or earth). Debris flows (commonly referred to as mudflows or mudslides) and rock falls are examples of common landslide types.

Moraine

Moraines are accumulations of dirt and rocks that have fallen onto the glacier surface or have been pushed along by the glacier as it moves. The dirt and rocks composing moraines can range in size from powdery silt to large rocks and boulders. A receding glacier can leave behind moraines that are visible long after the glacier retreats.

Mountain

Mountain formation refers to the geological processes that underlie the formation of mountains. These processes are associated with large-scale movements of the Earth's crust (tectonic plates). Folding, faulting, volcanic activity, igneous intrusion and metamorphism can all be parts of the orogenic process of mountain building. The formation of mountains is not necessarily related to the geological structures found on it.

Volcano

A volcano is a rupture in the Earth’s crust which allows magma/ash/gases to escape from beneath the surface. When magma reaches the surface of the Earth, it is called lava.

Most volcanoes occur along or near the margins of tectonic plates, where plates move away from each other or collide. We have a number of resources relating to volcanoes, available from the links below and to the right. Find out about the worldwide distribution of volcanoes; historic volcanic events; and the products, prediction and hazards associated with volcanoes.

Waterfall

Waterfall, area where flowing river water drops abruptly and nearly vertically. Waterfalls represent major interruptions in river flow. Under most circumstances, rivers tend to smooth out irregularities in their flow by processes of erosion and deposition. In time, the long profile of a river (the graph of its gradient) takes the form of a smooth curve, steepest toward the source, gentlest toward the mouth. Waterfalls interrupt this curve, and their presence is a measure of the progress of erosion. A waterfall may also be termed a falls or sometimes a cataract, the latter designation being most common when large volumes of water are involved. Waterfalls of small height and lesser steepness are called cascades; this term is often applied to a series of small falls along a river.