{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/97624"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/97624","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Temporal change of the earth’s inner core from repeating earthquakes","abstract":"This Thesis was approved for publication on 2017-04-24 at 15:38.","abstract_html":"This Thesis was approved for publication on 2017-04-24 at 15:38.","abstract_has_math":false,"creators":["Yang, Yi"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Geology","degree_department":null,"school":null,"contributors":["Song, Xiaodong"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2017,"date_issued":"2017-08-10T19:52:21Z","date_published":"2017-08-10T19:52:21Z","updated_at":"2026-07-22T22:24:34Z","subjects":["Inner core","Repeating earthquakes"],"languages":["en"],"rights":["Copyright 2017 Yi Yang"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/97624","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Song, Xiaodong"]},{"key":"dc:creator","label":"Author","values":["Yang, Yi"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2017-08-10T19:52:21Z","2019-08-11T09:15:21Z","2017-04-24","2017-05"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Geology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Inner core","Repeating earthquakes"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2017 Yi Yang"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/97624"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["This Thesis was approved for publication on 2017-04-24 at 15:38.","DSpace SAF Submission Ingestion Package generated from Vireo submission #10993 on 2017-08-10 at 14:32:30","Made available in DSpace on 2017-08-10T19:52:21Z (GMT). No. of bitstreams: 2 YANG-THESIS-2017.pdf: 5309569 bytes, checksum: d1365a4c564a5835961c92808f10029e (MD5) LICENSE.txt: 4204 bytes, checksum: 8116c02108370f444b1fad9a7132d412 (MD5) Previous issue date: 2017-04-24","Embargo set by: Colleen Fallaw for item 102677 Lift date: 2019-08-10T21:25:30Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system","The differential motion, lateral velocity gradient, and topography of the Earth’s inner core make the temporal change of the core phases’ arrival times observable in waveform doublets, a pair of events happened at the same location and recorded by the same stations. Using doublets searched from the events in the South Sandwich Island (SSI) region recorded by the station COLA, we observed systematic temporal variations and recalculated the inner core’s differential spin rate relative to the mantle as 0.2-0.4 degree/yr, which is slightly smaller than that estimated by previous study of Zhang et al. (2005). We also analyzed the topography of the inner core boundary (ICB) beneath Africa with the doublets recorded by seismic stations in Asia. There are obvious temporal changes of the ICB, which may indicate the melting and freezing of the ICB in recent decades.","Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2019-05-01","The student, Yi Yang, accepted the attached license on 2017-04-21 at 16:16.","The student, Yi Yang, submitted this Thesis for approval on 2017-04-21 at 16:20.","Limited Restriction Lifted for Item 102677 on 2019-08-11T09:15:21Z."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Temporal change of the earth’s inner core from repeating earthquakes"]}]}],"canonical_facts":{"dc:contributor":["Song, Xiaodong"],"dc:creator":["Yang, Yi"],"dc:date":["2017-08-10T19:52:21Z","2019-08-11T09:15:21Z","2017-04-24","2017-05"],"dc:description":["This Thesis was approved for publication on 2017-04-24 at 15:38.","DSpace SAF Submission Ingestion Package generated from Vireo submission #10993 on 2017-08-10 at 14:32:30","Made available in DSpace on 2017-08-10T19:52:21Z (GMT). No. of bitstreams: 2 YANG-THESIS-2017.pdf: 5309569 bytes, checksum: d1365a4c564a5835961c92808f10029e (MD5) LICENSE.txt: 4204 bytes, checksum: 8116c02108370f444b1fad9a7132d412 (MD5) Previous issue date: 2017-04-24","Embargo set by: Colleen Fallaw for item 102677 Lift date: 2019-08-10T21:25:30Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system","The differential motion, lateral velocity gradient, and topography of the Earth’s inner core make the temporal change of the core phases’ arrival times observable in waveform doublets, a pair of events happened at the same location and recorded by the same stations. Using doublets searched from the events in the South Sandwich Island (SSI) region recorded by the station COLA, we observed systematic temporal variations and recalculated the inner core’s differential spin rate relative to the mantle as 0.2-0.4 degree/yr, which is slightly smaller than that estimated by previous study of Zhang et al. (2005). We also analyzed the topography of the inner core boundary (ICB) beneath Africa with the doublets recorded by seismic stations in Asia. There are obvious temporal changes of the ICB, which may indicate the melting and freezing of the ICB in recent decades.","Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2019-05-01","The student, Yi Yang, accepted the attached license on 2017-04-21 at 16:16.","The student, Yi Yang, submitted this Thesis for approval on 2017-04-21 at 16:20.","Limited Restriction Lifted for Item 102677 on 2019-08-11T09:15:21Z."],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/97624"],"dc:language":["en"],"dc:rights":["Copyright 2017 Yi Yang"],"dc:subject":["Inner core","Repeating earthquakes"],"dc:title":["Temporal change of the earth’s inner core from repeating earthquakes"],"dc:type":["text"],"thesis:degree_discipline":["Geology"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:34Z"}