{"id":6222,"date":"2026-10-19T09:48:39","date_gmt":"2026-10-19T09:48:39","guid":{"rendered":"https:\/\/phd.hi.is\/doktorsvorn\/doktorsvorn-i-jardfraedi-maja-bar-rasmussen\/"},"modified":"2026-10-19T09:48:39","modified_gmt":"2026-10-19T09:48:39","slug":"doktorsvorn-i-jardfraedi-maja-bar-rasmussen","status":"publish","type":"phd_defence","link":"https:\/\/phd.hi.is\/en\/doktorsvorn\/doktorsvorn-i-jardfraedi-maja-bar-rasmussen\/","title":{"rendered":"Doktorsv\u00f6rn \u00ed jar\u00f0fr\u00e6\u00f0i – Maja Bar Rasmussen"},"content":{"rendered":"
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Streymi:\u00a0<\/strong>https:\/\/livestream.com\/hi\/doktorsvornmajabarrasmussen<\/a><\/p>\n

Doktorsefni:<\/strong>\u00a0Maja Bar Rasmussen<\/p>\n

Heiti ritger\u00f0ar:<\/strong>\u00a0Misleitni m\u00f6ttulsins undir \u00cdslandi ranns\u00f6ku\u00f0 me\u00f0 \u00f3liv\u00ednkrist\u00f6llum
(Magmatic olivine as a tool to investigate geochemical mantle heterogeneities beneath Iceland)<\/p>\n

Andm\u00e6lendur:<\/strong>
Dr. Abigail Barker, d\u00f3sent vi\u00f0 Jar\u00f0v\u00edsindadeild, Uppsalah\u00e1sk\u00f3la, Sv\u00ed\u00fej\u00f3\u00f0
Dr. Kevin Burton, pr\u00f3fessor vi\u00f0 Jar\u00f0v\u00edsindadeild Durham University, Bretlandi<\/p>\n

Lei\u00f0beinandi:<\/strong>\u00a0Dr. S\u00e6mundur Ari Halld\u00f3rsson, fr\u00e6\u00f0ima\u00f0ur vi\u00f0 Jar\u00f0v\u00edsindastofnun H\u00e1sk\u00f3lans<\/p>\n

Einnig \u00ed doktorsnefnd:
<\/strong>Dr. Sally A. Gibson, pr\u00f3fessor vi\u00f0 Jar\u00f0v\u00edsindadeild University of Cambridge, Bretlandi
Dr. Gu\u00f0mundur H. Gu\u00f0finnsson, fr\u00e6\u00f0ima\u00f0ur vi\u00f0 Jar\u00f0v\u00edsindastofnun H\u00e1sk\u00f3lans<\/p>\n

Doktorsv\u00f6rn st\u00fdrir:<\/strong>\u00a0Dr. Freysteinn Sigmundsson, v\u00edsindama\u00f0ur vi\u00f0 Jar\u00f0v\u00edsindastofnun og deildarforseti Jar\u00f0v\u00edsindadeildar H\u00e1sk\u00f3la \u00cdslands<\/p>\n

\u00c1grip<\/strong><\/p>\n

Vel er \u00feekkt a\u00f0 s\u00f6kk \u00fathafsfleka ni\u00f0ur \u00ed m\u00f6ttulinn \u00e1 ni\u00f0urstreymisflekam\u00f3tum lei\u00f0ir til aukins breytileika \u00ed efna- og steindasamsetningu m\u00f6ttuls jar\u00f0ar. Hins vegar hefur fr\u00e6\u00f0asamf\u00e9lagi\u00f0 lengi deilt um hvert umfang sl\u00edks endurunnins efnis s\u00e9 \u00ed jar\u00f0m\u00f6ttlinum og a\u00f0 hve miklu leyti og \u00e1 hva\u00f0a h\u00e1tt \u00fea\u00f0 skilar s\u00e9r aftur til yfirbor\u00f0s \u00ed gegnum dj\u00fap\u00e6tta\u00f0ar r\u00e6tur \u00fathafseyja.
Steindin \u00f3l\u00edv\u00edn er a\u00f0 \u00f6llu j\u00f6fnu me\u00f0al fyrstu fasa sem kristallast \u00far m\u00f6ttul\u00e6tta\u00f0ri bergbr\u00e1\u00f0 \u00e1 lei\u00f0 til yfirbor\u00f0s. H\u00fan er st\u00f6\u00f0ug yfir langt hita- og \u00fer\u00fdstingsbil \u00e1samt \u00fev\u00ed a\u00f0 efnasamsetning hennar r\u00e6\u00f0st af \u00feeirri br\u00e1\u00f0 sem h\u00fan kristallast \u00far. \u00deannig hefur veri\u00f0 s\u00fdnt fram \u00e1 a\u00f0 nota megi a\u00f0al- og snefilefnasamsetningu \u00f3liv\u00ednkristalla til a\u00f0 endurskapa \u00fe\u00e6r frumbr\u00e1\u00f0ir sem \u00f3liv\u00edni\u00f0 kristalla\u00f0ist \u00far og a\u00f0 efnasamsetningin markist l\u00edtt af seinni kvikuferlum.<\/p>\n

\u00cdsland er \u00f3venjulega umfangsmikil landspilda \u00fear sem \u00fathafshryggur liggur ofansj\u00e1var. \u00c1st\u00e6\u00f0a \u00feess er s\u00fa a\u00f0 \u00cdsland er heitur reitur sem talinn er stafa af dj\u00fapst\u00e6\u00f0um m\u00f6ttulstr\u00f3k sem flytur varma og efni \u00ed \u00e1tt a\u00f0 yfirbor\u00f0i. \u00c1 grundvelli \u00e1ratuga ranns\u00f3kna \u00e1 \u00edslensku basalti hefur s\u00fdnt fram \u00e1 a\u00f0 m\u00f6ttullinn undir \u00cdslandi er efnafr\u00e6\u00f0ilega misleitur og \u00far honum ver\u00f0i til margv\u00edslegar br\u00e1\u00f0ir. Einnig hafa veri\u00f0 leiddar a\u00f0 \u00fev\u00ed l\u00edkur a\u00f0 meginhluta \u00feessarar misleitni \u00ed m\u00f6ttli megi rekja til br\u00e1\u00f0nunar \u00e1 \u00fathafsflekaefni sem or\u00f0i\u00f0 er hluti af \u00edslenska m\u00f6ttulstr\u00f3knum eftir a\u00f0 hafa sokki\u00f0 \u00ed ni\u00f0urstreymisbeltum. \u00c1 \u00cdslandi eru frumst\u00e6\u00f0ar bergtegundir sem \u00ed m\u00e1 finna \u00f3liv\u00ednkristalla nokku\u00f0 algengar. \u00dev\u00ed eru h\u00e9r kj\u00f6ra\u00f0st\u00e6\u00f0ur til \u00feess a\u00f0 kanna frekar umfang endurunnins efnis \u00ed m\u00f6ttli og hvernig ummerki um \u00fea\u00f0 var\u00f0veitast \u00ed \u00f3liv\u00ednkrist\u00f6llum.<\/p>\n

\u00cd \u00feessari ritger\u00f0 eru lag\u00f0ar fram \u00ferj\u00e1r greinar \u00fear sem frumst\u00e6\u00f0ir \u00f3liv\u00ednkristallar er r\u00e6kilega kanna\u00f0ir me\u00f0 \u00feessar hugmyndir a\u00f0 lei\u00f0arlj\u00f3si. H\u00e1g\u00e6\u00f0ag\u00f6gnum, sem samanstanda a\u00f0allega af \u00f6rgreiningum \u00e1 krist\u00f6llum \u00e1samt heildarefnagreiningum \u00e1 st\u00f6kum krist\u00f6llum, var safna\u00f0 og \u00feau t\u00falku\u00f0 me\u00f0 \u00fea\u00f0 a\u00f0 markmi\u00f0i a\u00f0 endurskapa sem best efnasamsetningar m\u00f6ttul\u00e6tta\u00f0ra br\u00e1\u00f0a. \u00cd fyrsta kafla eru kynntar ni\u00f0urst\u00f6\u00f0ur \u00f6rgreininga \u00e1 a\u00f0al- og snefilefnum me\u00f0 \u00e1\u00f0ur birtum hel\u00edumsams\u00e6tug\u00f6gnum. Samt\u00falkun \u00feessara \u00f3l\u00edku gagnasafna varpar lj\u00f3si \u00e1 uppbyggingu \u00edslenska m\u00f6ttulstr\u00f3ksins og umfang endurunnins efnis sem finna m\u00e1 \u00ed honum.<\/p>\n

\u00cd kafla tv\u00f6 notf\u00e6ri \u00e9g m\u00e9r s\u00farefnissams\u00e6tugreiningar \u00e1 s\u00f6mu krist\u00f6llum, ger\u00f0ar me\u00f0 j\u00f3napr\u00f3b\/\u00f6rgreini, til a\u00f0 kanna vensl s\u00farefnissams\u00e6ta, samsetningu kristalla og hel\u00edumsams\u00e6ta. S\u00farefnissams\u00e6tur gera okkur kleift a\u00f0 meta enn betur umfang endurunnins efnis sem \u00edslenski m\u00f6ttulstr\u00f3kurinn dregur me\u00f0 s\u00e9r. Samt\u00falkun me\u00f0 hel\u00edumsams\u00e6tum s\u00fdnir jafnframt fram \u00e1 hvernig riskraftur og afl \u00edslenska m\u00f6ttulstr\u00f3ksins j\u00f3kst samhli\u00f0a opnun Nor\u00f0ur-Atlantshafsins og myndun \u00cdslandsh\u00e1sl\u00e9ttunnar.<\/p>\n

\u00cd \u00feri\u00f0ja kafla kanna \u00e9g m\u00f6guleika \u00e1 a\u00f0 nota Mg- og Fe-sams\u00e6tugreininga \u00e1 st\u00f6kum krist\u00f6llum til a\u00f0 skor\u00f0a betur efnaeiginleika endurunna efnisins sem finna m\u00e1 \u00ed \u00edslenska m\u00f6ttlinum. S\u00fdnt er fram \u00e1 a\u00f0 samhli\u00f0a risi br\u00e1\u00f0a og efnasveimi, sem \u00e1 s\u00e9r sta\u00f0 milli br\u00e1\u00f0ar og n\u00e6rliggjandi kristalla, ey\u00f0ast flest\u00f6ll ummerki \u00feessa eiginleika m\u00f6ttulefnisins. Hins vegar benda \u00feessar ni\u00f0urst\u00f6\u00f0ur til \u00feess a\u00f0 vensl s\u00e9u milli dvalart\u00edma kristalla og sams\u00e6tuhlutfalla, sem opnar \u00e1 \u00feann m\u00f6guleika a\u00f0 nota megi Mg- og Fe-sams\u00e6tugreiningar til a\u00f0 leggja mat \u00e1 dvalart\u00edma br\u00e1\u00f0a.<\/p>\n

Um doktorsefni\u00f0<\/strong><\/p>\n

Maja Bar Rasmussen \u00fatskrifa\u00f0ist me\u00f0 meistaragr\u00e1\u00f0u \u00ed jar\u00f0fr\u00e6\u00f0i-jar\u00f0v\u00edsindum fr\u00e1 Kaupmannahafnarh\u00e1sk\u00f3la \u00e1ri\u00f0 2015, me\u00f0 \u00e1herslu \u00e1 jar\u00f0efnafr\u00e6\u00f0i og eldfjallafr\u00e6\u00f0i. A\u00f0 n\u00e1mi loknu starfa\u00f0i h\u00fan vi\u00f0 Jar\u00f0v\u00edsindastofnun Danmerkur og Gr\u00e6nlands (GEUS) \u00e1\u00f0ur en h\u00fan h\u00f3f doktorsn\u00e1m vi\u00f0 H\u00e1sk\u00f3la \u00cdslands sem styrk\u00feegi Norr\u00e6na Eldfjallasetursins.<\/p>\n<\/div><\/div>","protected":false},"featured_media":4987,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_phd_date_start":"2021-01-22T14:00:00+00:00","_phd_date_end":"2021-01-22T16:00:00+00:00","_phd_location":"A\u00f0albygging H\u00e1t\u00ed\u00f0arsalur","_phd_admission":"A\u00f0gangur \u00f3keypis","_phd_thesis_title":"Misleitni m\u00f6ttulsins undir \u00cdslandi ranns\u00f6ku\u00f0 me\u00f0 \u00f3liv\u00ednkrist\u00f6llum (Magmatic olivine as a tool to investigate geochemical mantle heterogeneities beneath Iceland)","_phd_source_url":"https:\/\/gamli.hi.is\/vidburdir\/doktorsvorn_i_jardfraedi_maja_bar_rasmussen","_phd_source_node_id":"372537","_phd_source_type":"vidburdir","_phd_member_id":746,"footnotes":""},"phd_school":[113,93],"phd_discipline":[115],"class_list":["post-6222","phd_defence","type-phd_defence","status-publish","has-post-thumbnail","hentry","phd_school-jardvisindadeild","phd_school-verkfraedi-og-natturuvisindasvid","phd_discipline-phd-i-jardfraedi"],"_links":{"self":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6222","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence"}],"about":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/types\/phd_defence"}],"version-history":[{"count":0,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6222\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media\/4987"}],"wp:attachment":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media?parent=6222"}],"wp:term":[{"taxonomy":"phd_school","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_school?post=6222"},{"taxonomy":"phd_discipline","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_discipline?post=6222"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}