Autocorrelation Reflectivity of Mars

Abstract

The seismic structure of the Martian interior can shed light on the formation and dynamic evolution of the planet and our solar system. The deployment of the seismograph carried by the InSight mission provides a means to study Martian internal structure. We used ambient noise autocorrelation to analyze the available vertical component seismic data to recover the reflectivity beneath the Insight lander. We identify the noise that is approximately periodic with the Martian sol as daily lander operations and the diurnal variation in Martian weather and tides. To investigate the seismic discontinuities at different depths, the autocorrelograms are filtered and stacked into different frequency bands. We observe prominent reflection signals probably corresponding to the Martian Moho, the olivine‐wadsleyite transition in the mantle, and the core‐mantle boundary in the stacked autocorrelograms. We estimate the depths of these boundaries as ~35, 1,110–1,170, and 1,520–1,600 km, consistent with other estimates.

Autocorrelation of the Ground Vibrations Recorded by the SEIS‐InSight Seismometer on Mars

“…We now critically examine our interpretation as well as those proposed in the recent literature. The work by Deng and Levander (2020) is particularly relevant to ours.…”

Utilizing distributed acoustic sensing and ocean bottom fiber optic cables for submarine structural characterization

“…Analysis of these signals might provide a path to understanding processes in the water column including ocean currents and coastal dynamics. Ambient noise autocorrelation methods have been successfully harnessed to extract reflectors from deep structure in past studies utilizing broadband or short period seismometers 45,46,52,53 . However, this family of techniques has of yet to be succesfully applied to surface DAS data, which tend to be dominated by surface waves.…”

“…been successfully applied to image subsurface structure on both the Earth and Mars 45,46 , and have recently been used with DAS data offshore the Sanriku coast of Japan to image marine sediment thickness and velocity properties 35 . We obtain autocorrelation (zero offset cross-correlation) functions along the densely sampled DAS array ( Fig.…”

Utilizing Distributed Acoustic Sensing and Ocean Bottom Fiber Optic Cables for Submarine Structural Characterization

“…Analysis of these signals might provide a path to understanding processes in the water column including ocean currents and coastal dynamics. Ambient noise autocorrelation methods have been successfully harnessed to extract reflectors from deep structure in past studies utilizing broadband or short period seismometers [52,53,46,45]. However, this family of techniques…”

“…Ambient noise autocorrelation technique has been successfully applied to image subsurface structure on Earth and Mars [45,46], and has recently been used with DAS data offshore the Sanriku coast of Japan to image marine sediment thickness and velocity properties [35]. We obtain autocorrelation (zero offset cross-correlation) functions along the densely sampled DAS array ( Fig.4a), as by-products of ambient noise cross-correlation.…”