Constraints on the mantle transition zone structure using triplicated body waves
<p>The mantle transition zone (MTZ) is bounded by seismic discontinuities at average depths of 410 km and 660 km, which are generally associated with major mantle mineral transformations.&#160;A body wave impinging from above on these discontinuities develops a refracted and reflected branch, leading to multiple arrivals of the same wavetype within a short time window.&#160;These so-called triplicated body waves are observed at regional epicentral distances (15-30&#176;) and carry information on MTZ structure due to their strong interaction with the 410 km and 660 km discontinuities.&#160;Careful data selection and processing as well as the assessment of source parameters are necessary steps in obtaining a high quality triplication data set.&#160;In this study, we consider recordings of events in Central America at permanent and transportable USArray stations, which are inverted for mantle structure.&#160;Our methodology is based on a joint consideration of mineral physics and seismic data in a probabilistic inversion framework and allows for determination of mantle thermo-chemical and seismic velocity structure.&#160;We present constraints on the mantle structure underneath the Gulf of Mexico.</p>