World Library  
Flag as Inappropriate
Email this Article

Slab pull

Article Id: WHEBN0025025301
Reproduction Date:

Title: Slab pull  
Author: World Heritage Encyclopedia
Language: English
Subject: Plate tectonics, Physical oceanography, Slab (geology), Geodynamics, Afar Triple Junction
Collection: Geodynamics, Geology Theories, Geophysics, Plate Tectonics
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Slab pull

Slab pull is the portion of motion of a tectonic plate that can be accounted for by its subduction. Plate motion is partly driven by the weight of cold, dense plates sinking into the mantle at trenches.[1][2] This force and slab suction account for almost all of the force driving plate tectonics. The ridge push at rifts contributes only 5 to 10%.[3]

Carlson et al. (1983) in Lallemandet al. (2005) defines the slab pull force as:

F_{sp} = K \times \Delta\rho \times L \times \sqrt{A}

Where:

K is 4.2g (the gravitational acceleration force = 9.81 m/s2) according to McNutt (1984);
Δρ = 80 kg/m3 is the mean density difference between the slab and the surrounding asthenosphere;
L is the slab length calculated only for the part above 670 km (the upper/lower mantle boundary);
A is the slab age in Ma at the trench.

The slab pull force manifests itself between two extreme forms:

Between these two examples there is the evolution of the Farallon plate: from the huge slab width with the Nevada, the Sevier and Laramide orogenies; the Mid-Tertiary ignimbrite flare-up and later left as Juan de Fuca and Cocos plates, the Basin and Range Province under extension, with slab break off, smaller slab width, more edges and mantle return flow.

Some early models of plate tectonics envisioned the plates riding on top of convection cells like conveyor belts. However, most scientists working today believe that the asthenosphere does not directly cause motion by the friction of such basal forces. The North American Plate is nowhere being subducted, yet it is in motion. Likewise the African, Eurasian and Antarctic Plates. The subducting slabs around the Pacific Ring of Fire cool down the Earth and its Core-mantle boundary, around the African Plate the upwelling mantle plumes from the Core-mantle boundary produce rifting. The overall driving force for plate motion and its energy source remain subjects of ongoing research.

References

  • Schellart, W. P.; Stegman, D. R.; Farrington, R. J.; Freeman, J.; Moresi, L. (16 July 2010). "Cenozoic Tectonics of Western North America Controlled by Evolving Width of Farallon Slab". Science 329 (5989): 316–319.  
  • "Breakthrough Achieved in Explaining Why Tectonic Plates Move the Way They Do". ScienceDaily. 17 July 2010. 
  • Conrad CP, Lithgow-Bertelloni C (2002). "How Mantle Slabs Drive Plate Tectonics". Science 298 (5591): L45.  
  • Clinton P. Conrad, Susan Bilek, Carolina Lithgow-Bertelloni (2004). "Great earthquakes and slab pull: interaction between seismic coupling and plate-slab coupling". Earth and Planetary Science Letters 218: 109–122.  
  • Lallemand, S., A. Heuret, and D. Boutelier (2005). "On the relationships between slab dip, back-arc stress, upper plate absolute motion, and crustal nature in subduction zones". Geochemistry Geophysics Geosystems 6: Q09006.  
  •  
  • Carlson, R. L., T. W. C. Hilde, and S. Uyeda (1983). "The driving mechanism of plate tectonics: Relation to age of the lithosphere at trench". Geophys. Res. Lett. 10: 297–300.  
  1. ^ Conrad CP, Lithgow-Bertelloni C (2002)
  2. ^ "Plate tectonics, based on 'Geology and the Environment', 5 ed; 'Earth', 9 ed". 
  3. ^ Conrad CP, Lithgow-Bertelloni C (2004)


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 USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov 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 Project Gutenberg 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.