Tectonic hazard physical impact

Different types of volcanoes form depending on the type of plate margin that has caused the eruption (divergent, convergent and transform platte margins.)

A volcano is formed when magma, which is melted mantle rock rises to the surface. Shield Volcanoes- divergent plate margins. These volcanoes erupt from a vent. The shape is formed from the erupted lava solidifying, because the lava is fluid it moves quickly and so covers long distances giving it a gently sloping sides characteristic- Philip Allan text book Composite volcano/cinder cone volcano- convergent margins. Formed from built up layers of solidified lava, rock and volcanic ash released from the volcanoes vent over time. The lava released is slow moving and cools quickly making it look like a cone. These volcanoes tend to be he most explosive Caldera volcano- These form when so much lava is erupted so rapidly it partially empties the underlying magma chamber. When this happens the summit of the volcanic structure collapses into the emptied magma chamber This leaves it having a dipped crater near the summit which fills with water.

Shield volcano e.g. Mauna-Loa, Hawaii Not very steep slope gradient. Widespread due to the fast running lava that is released..

Composite/ Cinder cone volcano e.g. Mount Fuji, Japan Steep cone shape created by the build up of lava. Vent where the magma is released.

Caldera volcano e.g. Yellowstone, America Large crater formed from the collapsed rock. Effects of the destructive explosion on the surrounding land. Sloped sides from the solidified magma.

Effects of Earthquakes on landscapes Amber Daynes Figure 1. diagram of international fault lines

Earthquakes Earthquakes occur as a result of friction between plate boundaries that builds as a result of movement between the plates. There are 3 different types of plate boundary – convergent, divergent and transcurrent.

Earthquakes Figure 2. A map showing eastern Africa and plate boundaries A rift valley forms where the earths crust or outermost layer is spreading or splitting apart. This kind of valley is often narrow with steep sides and a flat floor. From figure 2 we can see a rift valley that has formed from surrounding plate boundaries in Eastern Africa. valley/?ar_a=1

Earthquakes Video showing the movement in the ground during the Tohoku-oki Earthquake Figure 3 – showing ground displacement caused by the tohoku oki earthquake

Intrusive Igneous Activity Intrusive landforms are formed by magma rising towards the surface but cooling and solidifying before being extruded onto the surface. Background: mrkingsciencestudentbuiltsites.weebly.com/215-ej.html

Impact of Intrusive Igneous Activity Batholiths are huge scale features where magma is intruded into the ground and cool very slowly, giving coarse grained rocks with large crystals. If magma is squeezed HORIZONTALLY along bedding planes through layers of existing rock a layer of rock can cool which is known as a Sill. If magma is squeezed VERTICALLY upwards cutting across bedding planes of sedimentary rocks a Dyke is created.

Extrusive It is the outpouring of material from the Earth’s crust which produces variety of landforms. The major types are all volcanoes of various shapes and forms, but there are much smaller types too.

Impact of Extrusive Igneous Activity Their impact on the landscape depends on a number of factors, including the magnitude and scale of the event(s) causing them and the types of material being extruded. Examples are volcanoes of various shapes and forms Distribution is determined by the pattern of tectonic plates

Volcanic Formations Lava plateau: -Volcanic Cone They are built by fragments ejected from a volcanic vent, piling up around the vent in the shape of a cone with a central crater. sciencestudentbuiltsites.weebly.com/215-ej.html

Fissures: Eruptive fissure on southeast rim of Kilauea caldera, Hawaii. This eruptive fissure was active during July 1974 eruption. For all: