Publication Date:
2018-06-29
Description:
Publication date: 15 September 2018 Source: Earth and Planetary Science Letters, Volume 498 Author(s): Kirsten Schulze, Hauke Marquardt, Takaaki Kawazoe, Tiziana Boffa Ballaran, Catherine McCammon, Monika Koch-Müller, Alexander Kurnosov, Katharina Marquardt Ringwoodite, the dominant mineral at depths between 520 km and 660 km, can store up to 2–3 wt.% of water in its crystal structure, making the Earth's transition zone a plausible water reservoir that plays a central role in Earth's deep water cycle. Experiments show that hydration of ringwoodite significantly reduces elastic wave velocities at room pressure, but the effect of pressure remains poorly constrained. Here, a novel experimental setup enables a direct quantification of the effect of hydration on ringwoodite single-crystal elasticity and density at pressures of the Earth's transition zone and high temperatures. Our data show that the hydration-induced reduction of seismic velocities almost vanishes at conditions of the transition zone. Seismic data thus agree with a wide range of water contents in the transition zone.
Print ISSN:
0012-821X
Electronic ISSN:
1385-013X
Topics:
Geosciences
,
Physics
