Jump to content

Geography vocabulary: Difference between revisions

→‎volcano: building up section
(→‎Geography Fun Facts & Oddities: changing to Human population from fun facts (which is its own page now))
(→‎volcano: building up section)
Line 272: Line 272:
=== volcano ===
=== volcano ===


* formed when magma from below breaks through the earth's crust
** lava, ash, and gasses escape
** as lava accumulates, volcanic mountains, below and above the sea form
* the earth's crust itself is originally built of lava
** = "igneous rock"
*** "igeneous" is from ''ignis'', Latin for "fire"
*** other rock types:
**** sedimentary = layered minerals and organic material
**** metamorphic = new rock types formed by pressure and heat of existing rocks
* breaks in the earth's crust are caused by [[File:World Distribution of Mid-Oceanic Ridges.gif|thumb|World distribution of mid-oceanic ridges]]
** shifts in and colliding of tectonic plates
** thus places where the plates are either separating for converging, such as:
*** separating = mid-oceanic ridges, which surround several of the continents, including:
**** Mid-Atlantic ridge from Greenland to southern Atlantic, in the center of the Atlantic Ocean
**** Pacific ridges, which extend from Baha California south and east, below Australia and connecting with the mid-Oceanic ridges of the Indian Ocean
*** converging (crashing into one another), such as:
**** the "Ring of Fire"
** weakening or thinning of the crust, such as:
*** East African Rift
*** Wells Gray-Clearwater volcanic field in British Columbia, Canada
*** Rio Grande Rift: from below the Colorado Plateau to the northern border of Mexico, covering most of New Mexico and parts of Arizona
**** note: the eastern edge of the Rio Grande Rift forms the North-South vertical portion of the New Mexico-Texas natural border
* Sources:
* Sources:
* [[https://www.nationalgeographic.org/encyclopedia/landform/ Landform (National Geographic)]]
* [[https://www.nationalgeographic.org/encyclopedia/landform/ Landform (National Geographic)]]