Search results
Results From The WOW.Com Content Network
A ravine is the final step in gully erosion, formed when a stream has eroded so severely it forms a deep cut in the earth. [3] A gully can be classified as a ravine after it reaches a large depth, typically in excess of 5 metres (16 ft).
In southern Louisiana the word coulée (also spelled coolie) originally meant a gully or ravine usually dry or intermittent but becoming sizable during rainy weather. As stream channels were dredged or canalized, the term was increasingly applied to perennial streams, generally smaller than bayous. The term is also used for small ditches or ...
The Greenstone Flow is one of the world's largest known lava flows, estimated at a volume ~1650 to ~6000 cubic kilometers of mafic lava. [2] [3] In places, the lava pooled to depth of 487 meters. [4] The flow was generated by a flood basalt eruption during the Midcontinental Rift, which occurred 1.1 billion years ago. [5]
Hornito – Conical structures built up by lava ejected through an opening in the crust of a lava flow; Kīpuka – Area of land surrounded by one or more younger lava flows; Lava – Molten rock expelled by a volcano during an eruption; Lava dome – Roughly circular protrusion from slowly extruded viscous volcanic lava
The two main types of lava field structures are defined as sheet flow lava and pillow lava. Sheet flow lava appears like a wrinkled or folded sheet, while pillow lava is bulbous, and often looks like a pile of pillows atop one another. [2] An important aspect of lava flow morphology is a phenomenon known as lava flow inflation. This occurs in ...
The lava that flows in lava channels is commonly basaltic in composition. Pāhoehoe lava flow on the Big Island of Hawaii The picture shows overflows from a main lava channel. The channel is crusting over with a v-shaped opening pointing upstream (top left). The main channel and overflows show the perched nature of this kind of lava channel.
The 2014 Holuhraun lava flow is a deep shade of purple, the 1797 Holuhraun lava flow is shaded slightly lighter, while other older Bárðarbunga associated lava flows are light purple. Shading also shows: calderas, other central volcanoes, fissure swarms, subglacial terrain above 1,100 m (3,600 ft) and seismically active areas between 1995 to 2007.
The volcanic field consists of two lava flows, the Broken Back flow and the Carrizozo lava flow (Carrizozo Malpais), the second youngest in New Mexico. [5] Both lava flows originated from groups of cinder cones. The Broken Back flow is approximately 16 kilometres (10 mi) long and the Carrizozo, one of the largest in the world, is 68 kilometres ...