Assessing the Role of Water in Alaskan Flat-Slab Subduction

4Citations
Citations of this article
18Readers
Mendeley users who have this article in their library.

Abstract

Low-angle subduction has been shown to have a profound impact on subduction processes. However, the mechanisms that initiate, drive, and sustain flat-slab subduction are debated. Within all subduction zone systems, metamorphic dehydration reactions within the down-going slab have been hypothesized to produce seismicity, and to produce water that fluxes melting of the asthenospheric wedge leading to arc magmatism. In this work, we examine the role hydration plays in influencing slab buoyancy and the geometry of the downgoing oceanic plate. When water is introduced to the oceanic lithosphere, it is incorporated into hydrous phases, which results in lowered rock densities. The net effect of this process is an increase in the buoyancy of the downgoing oceanic lithosphere. To better understand the role of water in low-angle subduction settings, we model flat-slab subduction in Alaska, where the thickened oceanic lithosphere of the Yakutat oceanic plateau is subducting beneath the continental lithosphere. In this work, we calculate the thermal conditions and stable mineral assemblages in the slab crust and mantle in order to assess the role that water plays in altering the density of the subducting slab. Our slab density results show that a moderate amount of hydration (1–1.5 wt% H2O) in the subducting crust and upper lithospheric mantle reduces slab density by 0.5%–0.8% relative to an anhydrous slab, and is sufficient to maintain slab buoyancy to 300–400 km from the trench. These models show that water is a viable factor in influencing the subduction geometry in Alaska, and is likely important globally.

References Powered by Scopus

An internally consistent thermodynamic data set for phases of petrological interest

4567Citations
N/AReaders
Get full text

An improved and extended internally consistent thermodynamic dataset for phases of petrological interest, involving a new equation of state for solids

1969Citations
N/AReaders
Get full text

Computation of phase equilibria by linear programming: A tool for geodynamic modeling and its application to subduction zone decarbonation

1856Citations
N/AReaders
Get full text

Cited by Powered by Scopus

Late Mesozoic diorites of the middle Gangdese magmatic belt of southern Tibet: New insights from SHRIMP U-Pb dating and Sr-Nd-Hf-O isotopes

5Citations
N/AReaders
Get full text

Controls on Bending-Related Faulting Offshore of the Alaska Peninsula

3Citations
N/AReaders
Get full text

Hydrogen solubility of stishovite provides insights into water transportation to the deep Earth

3Citations
N/AReaders
Get full text

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Cite

CITATION STYLE

APA

Petersen, S. E., Hoisch, T. D., & Porter, R. C. (2021). Assessing the Role of Water in Alaskan Flat-Slab Subduction. Geochemistry, Geophysics, Geosystems, 22(5). https://doi.org/10.1029/2021GC009734

Readers over time

‘21‘22‘23‘2402468

Readers' Seniority

Tooltip

Researcher 6

50%

PhD / Post grad / Masters / Doc 4

33%

Professor / Associate Prof. 2

17%

Readers' Discipline

Tooltip

Earth and Planetary Sciences 12

92%

Physics and Astronomy 1

8%

Save time finding and organizing research with Mendeley

Sign up for free
0