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The volume and height of hummocks is mostly dependent on their location; the closer to the source region, the larger they become. [10] The bottom layer of a debris avalanche deposit is the fine-grained matrix which forms due to the shear at the base of the large, turbulent moving mass.
Also amphidrome and tidal node. A geographical location where there is little or no tide, i.e. where the tidal amplitude is zero or nearly zero because the height of sea level does not change appreciably over time (meaning there is no high tide or low tide), and around which a tidal crest circulates once per tidal period (approximately every 12 hours). Tidal amplitude increases, though not ...
This glossary of geography terms is a list of definitions of terms and concepts used in geography and related fields, including Earth science, oceanography, cartography, and human geography, as well as those describing spatial dimension, topographical features, natural resources, and the collection, analysis, and visualization of geographic ...
A volcano needs a reservoir of molten magma (e.g. a magma chamber), a conduit to allow magma to rise through the crust, and a vent to allow the magma to escape above the surface as lava. The erupted volcanic material (lava and tephra) that is deposited around the vent is known as a volcanic edifice, typically a volcanic cone or mountain. [2] [22]
Satellite image of the Big Raven Plateau in British Columbia, Canada Rangipo Desert of the North Island Volcanic Plateau. Numerous tephra layers are visible. The Pajarito Plateau in New Mexico, United States is an example of a volcanic plateau. A volcanic plateau is a plateau produced by volcanic activity. There are two main types: lava ...
A volcanic plug, also called a volcanic neck or lava neck, is a volcanic object created when magma hardens within a vent on an active volcano. When present, a plug can cause an extreme build-up of high gas pressure if rising volatile -charged magma is trapped beneath it, and this can sometimes lead to an explosive eruption.
A volcanic field is an area of Earth's crust that is prone to localized volcanic activity. The type and number of volcanoes required to be called a "field" is not well-defined. [1] Volcanic fields usually consist of clusters of up to 100 volcanoes such as cinder cones. Lava flows may also occur.
Volcanologists frequently visit volcanoes, especially active ones, to observe volcanic eruptions, collect eruptive products including tephra (such as ash or pumice), rock and lava samples. One major focus of enquiry is the prediction of eruptions; there is currently no accurate way to do this, but predicting or forecasting eruptions, like ...