World Library  
Flag as Inappropriate
Email this Article

Pressure ridge (lava)

Article Id: WHEBN0024032028
Reproduction Date:

Title: Pressure ridge (lava)  
Author: World Heritage Encyclopedia
Language: English
Subject: The Volcano (British Columbia), Volcanology of Canada
Publisher: World Heritage Encyclopedia

Pressure ridge (lava)

Pressure ridge

A pressure ridge sometimes referred to as a tumulus (or tumuli in plural form) is created in an active lava flow.[1][2] Formation occurs when the outer edges and surfaces of the lava flow begin to harden.[1] If the advancing lava underneath becomes restricted it may push up on the hardened crust, tilting it outward.[1] Inflation also takes place and is a process where the plastic layer of lava underneath expands as it cools and small crystals form.[1] The end result is a raised mound of hardened lava rock, usually a relatively narrow but long ridge.[1] Tension cracks form on the surface of pressure ridges and run along the axis of elongated ridges, and at both edges of broader ridges, sometimes referred to as pressure plateaus.[1] Sometimes, along the edges of a pressure ridge, the tension crack can be large enough to create a liftup cave.[1] Other caves can form inside pressure ridges when the lava vacates leaving an inflationary cave.[3]


  1. ^ a b c d e f g
  2. ^
  3. ^

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.