{"id":3170,"date":"2024-09-25T07:56:46","date_gmt":"2024-09-25T14:56:46","guid":{"rendered":"https:\/\/faculty.epss.ucla.edu\/~cbeghein\/?page_id=3170"},"modified":"2024-09-25T07:57:31","modified_gmt":"2024-09-25T14:57:31","slug":"seismic-detection-of-a-deep-mantle-discontinuity-within-mars-by-insight","status":"publish","type":"page","link":"https:\/\/faculty.epss.ucla.edu\/~cbeghein\/seismic-detection-of-a-deep-mantle-discontinuity-within-mars-by-insight\/","title":{"rendered":"Seismic detection of a deep mantle discontinuity within Mars by InSight"},"content":{"rendered":"

Constraining the thermal and compositional state of the mantle is crucial for deciphering the formation and evolution of Mars. Since the depth of seismic discontinuities is sensitive to both mantle temperature and composition, their detection can provide unique constraints on the planet\u2019s interior. Using five teleseismic events recorded on Mars, we observed triplicated P and S waves, which reflect the presence of a seismic discontinuity in the Martian mantle.<\/p>\n

\"Depth<\/a>
Depth of the 1,000 discontinuity in Mars from mineral physics and synthetic waveform fits. (A) VP and (B) VS profiles from mineral physics models colored by the misfits of P and S triplications, respectively. Abbreviations for mantle minerals are as follows: olivine (ol), wadsleyite (wad), ringwoodite (rw), garnet (gt), clinopyroxene (cpx), orthopyroxene (opx), and high-pressure clinopyroxene (HP-cpx). The red dashed lines in A and B highlight the best-fitting models for P and S triplications, respectively. The velocity jump at \u223c1,000 km depth is associated with the postolivine transition. A shallower minor discontinuity at \u223c800 km corresponds to the opx to HP-cpx transition. (Insets) Crustal and upper mantle structures of the best-fitting model. Misfits of (C) P triplication, (D) S triplication, and (E) total misfits (weighted sum of the misfits of P and S triplications) are shown as a function of the 1,000 discontinuity depth. The colors represent the mantle potential temperature (), and the symbols correspond to six composition models<\/figcaption><\/figure>\n

Waveform modeling of the triplicated phases revealed a seismic discontinuity at a depth of 1,006 \u00b1 40 km.<\/strong> We found that it matches the expected depth and sharpness of the pressure-induced phase transformation of the mineral olivine <\/strong>(assumed to be dominant in the mantle) to its higher-pressure polymorphs (post-olivine transition). Our modeling indicated a broad gradient across the boundary, in line with the notion that the Martian mantle is more enriched in iron than Earth<\/strong>. I contributed to the writing of the Huang et al. (2022)<\/strong> PNAS <\/em>manuscript in which these results were presented.<\/p>\n

Huang, Q. et al. (2022),\u00a0Seismic detection of the Martian mantle transition zone by InSight, PNAS<\/em>, doi:10.1073\/pnas.2204474119.<\/p>\n","protected":false},"excerpt":{"rendered":"

Constraining the thermal and compositional state of the mantle is crucial for deciphering the formation and evolution of Mars. Since the depth of seismic discontinuities is sensitive to both mantle temperature and composition, their detection can provide unique constraints on the planet\u2019s interior. Using five teleseismic events recorded on Mars, we observed triplicated P and … <\/p>\n

Read more “Seismic detection of a deep mantle discontinuity within Mars by InSight”<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"inspiro_hide_title":false,"footnotes":""},"class_list":["post-3170","page","type-page","status-publish","hentry"],"jetpack_sharing_enabled":true,"featured_media_urls":[],"_links":{"self":[{"href":"https:\/\/faculty.epss.ucla.edu\/~cbeghein\/wp-json\/wp\/v2\/pages\/3170","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/faculty.epss.ucla.edu\/~cbeghein\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/faculty.epss.ucla.edu\/~cbeghein\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/faculty.epss.ucla.edu\/~cbeghein\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/faculty.epss.ucla.edu\/~cbeghein\/wp-json\/wp\/v2\/comments?post=3170"}],"version-history":[{"count":4,"href":"https:\/\/faculty.epss.ucla.edu\/~cbeghein\/wp-json\/wp\/v2\/pages\/3170\/revisions"}],"predecessor-version":[{"id":3175,"href":"https:\/\/faculty.epss.ucla.edu\/~cbeghein\/wp-json\/wp\/v2\/pages\/3170\/revisions\/3175"}],"wp:attachment":[{"href":"https:\/\/faculty.epss.ucla.edu\/~cbeghein\/wp-json\/wp\/v2\/media?parent=3170"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}