Mid-ocean ridge jumps associated with hotspot magmatism
MetadataShow full item record
Hotspot-ridge interaction produces a wide range of phenomena including excess crustal thickness, geochemical anomalies, off-axis volcanic ridges and ridge relocations or jumps. Ridges are recorded to have jumped toward many hotspots including, Iceland, Discovery, Galapagos, Kerguelen and Tristan de Cuhna. The causes of ridge jumps likely involve a number of interacting processes related to hotspots. One such process is reheating of the lithosphere as magma penetrates it to feed near-axis volcanism. We study this effect by using the hybrid, finite-element code, FLAC, to simulate two-dimensional (2-D, cross-section) viscous mantle flow, elasto-plastic deformation of the lithosphere and heat transport in a ridge setting near an off-axis hotspot. Heating due to magma transport through the lithosphere is implemented within a hotspot region of fixed width. To determine the conditions necessary to initiate a ridge jump, we vary four parameters: hotspot magmatic heating rate, spreading rate, seafloor age at the location of the hotspot and ridge migration rate. Our results indicate that the hotspot magmatic heating rate required to initiate a ridge jump increases non-linearly with increasing spreading rate and seafloor age. Models predict that magmatic heating, itself, is most likely to cause jumps at slow spreading rates such as at the Mid-Atlantic Ridge on Iceland. In contrast, despite the higher magma flux at the Galapagos hotspot, magmatic heating alone is probably insufficient to induce a ridge jump at the present-day due to the intermediate ridge spreading rate of the Galapagos Spreading Center. The time required to achieve a ridge jump, for fixed or migrating ridges, is found to be on the order of 105-106 years. Simulations that incorporate ridge migration predict that after a ridge jump occurs the hotspot and ridge migrate together for time periods that increase with magma flux. Model results also suggest a mechanism for ridge reorganizations not related to hotspots such as ridge jumps in back-arc settings and ridge segment propagation along the Mid-Atlantic Ridge.
Author Posting. © Elsevier B.V., 2007. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Earth and Planetary Science Letters 266 (2008): 256-270, doi:10.1016/j.epsl.2007.10.055.
Suggested CitationPreprint: Mittelstaedt, Eric, Ito, Garrett T., Behn, Mark D., "Mid-ocean ridge jumps associated with hotspot magmatism", 2007-10-11, https://doi.org/10.1016/j.epsl.2007.10.055, https://hdl.handle.net/1912/2131
Showing items related by title, author, creator and subject.
Characterization of sills associated with the U reflection on the Newfoundland margin : evidence for widespread early post-rift magmatism on a magma-poor rifted margin Peron-Pinvidic, Gwenn; Shillington, Donna J.; Tucholke, Brian E. (John Wiley & Sons, 2010-05-25)Drilling during ODP Leg 210 penetrated two post-rift sills (dated as ∼105.3 and ∼97.8 Ma) in the deep sediments overlying basement of the continent–ocean transition zone on the magma-poor Newfoundland margin. The sill ...
Volatile and trace elements in basaltic glasses from Samoa : implications for water distribution in the mantle Workman, Rhea K.; Hauri, Erik H.; Hart, Stanley R.; Wang, Jianhua; Blusztajn, Jerzy S. (2005-10-24)We report volatile (H2O, CO2, F, S, Cl) and trace element data for submarine alkalic basalt glasses from the three youngest Samoan volcanoes, Ta’u, Malumalu and Vailulu’u. Most samples are visibly sulfide saturated, so ...
Whales and waves : humpback whale foraging response and the shoaling of internal waves at Stellwagen Bank Pineda, Jesus; Starczak, Victoria R.; da Silva, Jose C. B.; Helfrich, Karl R.; Thompson, Michael A.; Wiley, David N. (John Wiley & Sons, 2015-04-02)We tested the hypothesis that humpback whales aggregate at the southern flank of Stellwagen Bank (SB) in response to internal waves (IWs) generated semidiurnally at Race Point (RP) channel because of the presence of their ...