Observation of a Core-Diffracted P-Wave From a Farside Impact With Implications for the Lower-Mantle Structure of Mars
OPEN ACCESS
Loading...
Author / Producer
Date
2022-11-16
Publication Type
Journal Article
ETH Bibliography
yes
Citations
Altmetric
OPEN ACCESS
Data
Rights / License
Abstract
We report on the observation of a diffracted P-wave (Pdiff) along the core of Mars from a distant impact that has been recorded by the Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) mission. The identification of Pdiff allows us to sample the P-wave velocity structure of the lower mantle that hitherto could not be constrained because of lack of lower-mantle-traversing P-waves. In addition to Pdiff, we are able to pick PP-, PPP-, and SS-wave arrivals and locate the event to the farside of Mars in the vicinity of Tharsis, in agreement with the imaged location of the impact. This indicates that our joint single-station seismic event-location and structure-inversion scheme is both robust and accurate. Based on inversion of the body-wave arrival time picks made here, we find lower P-wave velocities in the deep mantle relative to predictions based on thermochemically homogeneous models.
Permanent link
Publication status
published
External links
Editor
Book title
Journal / series
Volume
49 (21)
Pages / Article No.
Publisher
American Geophysical Union
Event
Edition / version
Methods
Software
Geographic location
Date collected
Date created
Subject
marsquakes; Mars' interior structure; seismic phases; body waves; inversion; lower mantle
Organisational unit
03476 - Giardini, Domenico (emeritus) / Giardini, Domenico (emeritus)