{"id":6116,"date":"2026-10-19T09:48:29","date_gmt":"2026-10-19T09:48:29","guid":{"rendered":"https:\/\/phd.hi.is\/doktorsvorn\/doktorsvorn-i-jardvisindum-hronn-egilsdottir\/"},"modified":"2026-10-19T09:48:29","modified_gmt":"2026-10-19T09:48:29","slug":"doktorsvorn-i-jardvisindum-hronn-egilsdottir","status":"publish","type":"phd_defence","link":"https:\/\/phd.hi.is\/en\/doktorsvorn\/doktorsvorn-i-jardvisindum-hronn-egilsdottir\/","title":{"rendered":"Doktorsv\u00f6rn \u00ed jar\u00f0v\u00edsindum – Hr\u00f6nn Egilsd\u00f3ttir"},"content":{"rendered":"
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Mi\u00f0vikudaginn 8. febr\u00faar ver Hr\u00f6nn Egilsd\u00f3ttir doktorsritger\u00f0 s\u00edna vi\u00f0 Jar\u00f0v\u00edsindadeild H\u00e1sk\u00f3la \u00cdslands. Ritger\u00f0in ber heiti\u00f0:\u00a0Kalkmyndandi l\u00edfverur \u00e1 breytilegrum b\u00fasv\u00e6\u00f0um grunn- og dj\u00fapsj\u00e1var (Calcifying organisms in changing shallow and deep marine environments).<\/p>\n

Andm\u00e6lendur eru dr. Jean-Pierre Gattuso, v\u00edsindama\u00f0ur vi\u00f0 Laboratoire d\u2019Oc\u00e9anographie de Villefranche, Frakklandi, og Stephen Widdicombe, pr\u00f3fessor og forst\u00f6\u00f0uma\u00f0ur \u201cL\u00edffr\u00e6\u00f0ilegs fj\u00f6lbreytileika og vistfr\u00e6\u00f0i\u201d vi\u00f0 Plymouth Marine Laboratory (PML), Englandi.<\/p>\n

Lei\u00f0beinandi er J\u00f3n \u00d3lafsson, pr\u00f3fessor emeritus vi\u00f0 Jar\u00f0v\u00edsindadeild H\u00e1sk\u00f3la \u00cdslands. Einnig s\u00e1tu \u00ed doktorsnefnd dr. Karl Gunnarsson, s\u00e9rfr\u00e6\u00f0ingur hj\u00e1 Hafranns\u00f3knarstofnun, og dr. \u00de\u00f3rarinn Sveinn Arnarson, verkefnastj\u00f3ri hj\u00e1 Orkustofnun.<\/p>\n

Magn\u00fas Tumi Gu\u00f0mundsson, pr\u00f3fessor og deildarforseti Jar\u00f0v\u00edsindadeildar H\u00e1sk\u00f3la \u00cdslands, st\u00fdrir v\u00f6rninni sem fram fer \u00ed H\u00e1t\u00ed\u00f0asal H\u00e1sk\u00f3la \u00cdslands og hefst kl. 13.00.<\/p>\n

\u00c1grip af ranns\u00f3kn<\/strong><\/p>\n

Kalkmyndandi l\u00edfverum stafar \u00f3gn af \u00feeim umhverfisbreytingum sem eru a\u00f0\u00a0ver\u00f0a \u00ed hafinu vegna st\u00f3rt\u00e6krar losunar mannkyns \u00e1 kold\u00edox\u00ed\u00f0i (CO2),\u00a0sem lei\u00f0ir s\u00ed\u00f0an til s\u00farnunar sj\u00e1varins og l\u00e6kkunar \u00e1 kalkmettun (\u2126)\u00a0\u00ed sj\u00f3. \u00deessari ritger\u00f0 er \u00e6tla\u00f0 a\u00f0 fylla upp \u00ed mikilv\u00e6g g\u00f6t \u00ed\u00a0\u00feekkingu okkar og efla \u00feannig skilning okkar \u00e1 aflei\u00f0ingum s\u00farnunar\u00a0sj\u00e1var fyrir kalkmyndandi l\u00edfr\u00edki innan \u00feriggja \u00f3l\u00edkra b\u00fasv\u00e6\u00f0a \u00ed og\u00a0vi\u00f0 sj\u00f3, \u00fe.e. fj\u00f6ru, grunns\u00e6vi og dj\u00fapsj\u00e1var.\u00a0Greinar I og II fjalla um fj\u00f6runa \u00fear sem umhverfisbreytingar geta veri\u00f0\u00a0b\u00e6\u00f0i hra\u00f0ar og vi\u00f0amiklar.<\/p>\n

Grein I l\u00fdsir \u00e1rst\u00ed\u00f0abundnum og daglegum\u00a0breytileika \u00ed efnajafnv\u00e6gi \u00f3l\u00edfr\u00e6ns kolefnis \u00ed fj\u00f6rupollum \u00ed tengslum\u00a0vi\u00f0 l\u00edffr\u00e6\u00f0ilega ferla hj\u00e1 kalkmyndandi rau\u00f0\u00fe\u00f6rungi (Ellisolandia\u00a0elongata). \u00cd grein II er l\u00fdst tilraun \u00fear sem \u00fe\u00f6rungar \u00far sama stofni\u00a0og voru aldir \u00ed 3 vikur vi\u00f0 mismunandi hlut\u00fer\u00fdsting CO2 (pCO2), 380 \u00b5atm\u00a0(n\u00faverandi styrk CO2 \u00ed andr\u00famslofti), og 550, 750 og 1000 \u00b5atm, e\u00f0a\u00a0styrk CO2 \u00ed andr\u00famslofti s\u00ed\u00f0ar \u00e1 21. \u00f6ldinni. Ni\u00f0urst\u00f6\u00f0ur\u00a0tilraunarinnar benda til \u00feess a\u00f0 kalkmyndandi \u00fe\u00f6rungar \u00ed fj\u00f6rum s\u00e9u minna vi\u00f0kv\u00e6mir fyrir CO2 styrk \u00ed andr\u00famslofti framt\u00ed\u00f0ar heldur en\u00a0tegundir sem finnast helst ne\u00f0an sj\u00e1varbor\u00f0s. Uppl\u00fdsingar vantar um n\u00e1tt\u00farulegan breytileika \u00e1 grunns\u00e6vi \u00ed\u00a0t\u00edma og r\u00fami, s\u00e9rstaklega hva\u00f0 var\u00f0ar \u00f3l\u00edfr\u00e6n kolefni. Sl\u00edkar\u00a0uppl\u00fdsingar eru mikilv\u00e6gar svo auka megi \u00e1 skilning \u00e1 \u00e1hrifum s\u00farnunar\u00a0sj\u00e1var \u00e1 l\u00edfr\u00edki \u00e1 grunns\u00e6vi og fyrir framlei\u00f0slu \u00e1 reiknil\u00edk\u00f6num\u00a0um fl\u00e6\u00f0i CO2 \u00e1 milli efnageyma.<\/p>\n

Grein III fjallar um \u00e1rst\u00ed\u00f0abundinn\u00a0umhverfisbreytileika \u00e1 grunns\u00e6vi vi\u00f0 \u00cdsland, Brei\u00f0afir\u00f0i. S\u00fdnt er fram\u00a0\u00e1 uppt\u00f6ku sj\u00e1var upp \u00e1 um 1.8 mol C m-2 \u00e1r-1 \u00e1 ranns\u00f3knarsv\u00e6\u00f0inu, en\u00a0pCO2 vi\u00f0 yfirbor\u00f0 m\u00e6ldist fr\u00e1 212 \u00b5atm um sumar til 417 \u00b5atm um vetur.\u00a0Dj\u00fapsj\u00f3rinn er tilt\u00f6lulega st\u00f6\u00f0ugt b\u00fasv\u00e6\u00f0i. \u00der\u00e1tt fyrir \u00fea\u00f0 benda\u00a0reiknil\u00edk\u00f6n til \u00feess a\u00f0 Nor\u00f0urh\u00f6f ver\u00f0i a\u00f0 mestu undirmettu\u00f0 me\u00f0\u00a0tilliti til kalkger\u00f0arinnar arag\u00f3n\u00edts fyrir \u00e1ri\u00f0 2100, sem telja m\u00e1 a\u00f0\u00a0\u00f3gni kalkmyndandi lind\u00fdrum \u00e1 \u00feessu sv\u00e6\u00f0i. \u00cd grein VI er l\u00fdst\u00a0tegundasamsetningu, dreifingu og fj\u00f6lbreytileika samloka og snigla \u00e1 h\u00e1um\u00a0breiddargr\u00e1\u00f0um \u00ed Nor\u00f0ur Atlantshafinu, \u00fe.e. nor\u00f0ur og su\u00f0ur af\u00a0Gr\u00e6nlands-\u00cdslands-F\u00e6reyja (GIF) hryggnum.<\/p>\n

\u00deessar uppl\u00fdsingar skapa grunn\u00a0fyrir \u00e1framhaldandi ranns\u00f3knir \u00e1 \u00e1hrifum umhverfisbreytinga \u00e1\u00a0kalkmyndandi lind\u00fdr \u00e1 \u00feeim sv\u00e6\u00f0um sem ranns\u00f6ku\u00f0 voru.\u00a0\u00c1 heildina liti\u00f0 veita \u00fe\u00e6r ranns\u00f3knir sem kynntar eru \u00ed \u00feessari\u00a0ritger\u00f0 uppl\u00fdsingar sem n\u00fdta m\u00e1 til \u00feess a\u00f0 \u00f6\u00f0last betri skilning \u00e1\u00a0m\u00f6gulegum \u00e1hrifum umhverfisbreytinga, og s\u00e9r \u00ed lagi s\u00farnunar sj\u00e1var, \u00e1\u00a0kalkmyndandi l\u00edfr\u00edki innan \u00feriggja b\u00fasv\u00e6\u00f0a \u00ed og vi\u00f0 sj\u00f3, \u00fe.e.\u00a0fj\u00f6ru, grunns\u00e6vi og dj\u00fapsj\u00e1var.<\/p>\n

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

Hr\u00f6nn Egilsd\u00f3ttir er f\u00e6dd \u00e1ri\u00f0 1983 \u00ed Reykjav\u00edk. Maki hennar er R\u00f3bert Cabrera og saman eiga \u00feau einn son, f\u00e6ddan \u00e1ri\u00f0 2013. H\u00fan lauk BS-gr\u00e1\u00f0u \u00ed l\u00edffr\u00e6\u00f0i fr\u00e1 H\u00e1sk\u00f3la \u00cdslands \u00e1ri\u00f0 2007 og meistaragr\u00e1\u00f0u (MRes) \u00ed sj\u00e1varl\u00edffr\u00e6\u00f0i fr\u00e1 H\u00e1sk\u00f3lanum \u00ed Plymouth \u00ed Englandi \u00e1ri\u00f0 2008. \u00c1ri\u00f0 2009 h\u00f3f h\u00fan doktorsn\u00e1m vi\u00f0 Jar\u00f0v\u00edsindadeild H\u00e1sk\u00f3la \u00cdslands og Hafranns\u00f3knastofnun. Markmi\u00f0 doktorsverkefnisins var a\u00f0 auka skilning \u00e1 \u00e1hrifum s\u00farnunar sj\u00e1var fyrir kalkmyndandi l\u00edfr\u00edki \u00ed hafinu.<\/p>\n

Doktorsverkefni\u00f0 var \u00ed upphafi styrkt af Evr\u00f3puverkefninu EPOCA og Hafranns\u00f3knastofnun. Verkefni\u00f0 hlaut einnig styrk \u00far Orkuranns\u00f3knarsj\u00f3\u00f0i Landsvirkjunar og \u00far N\u00e1tt\u00faruverndarsj\u00f3\u00f0i P\u00e1lma J\u00f3nssonar. Doktorsverkefni\u00f0 var s\u00ed\u00f0ar styrkt af Samt\u00f6kum fyrirt\u00e6kja \u00ed sj\u00e1var\u00fatvegi (SFS) sem einnig styrkja Hr\u00f6nn til \u00e1framhaldandi ranns\u00f3kna, \u00fe\u00e1 sem n\u00fddoktor vi\u00f0 Jar\u00f0v\u00edsindastofnun H\u00e1sk\u00f3la \u00cdslands.<\/p>\n<\/div><\/div>","protected":false},"featured_media":1940,"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":"","_phd_date_end":"","_phd_location":"A\u00f0albygging","_phd_admission":"A\u00f0gangur \u00f3keypis","_phd_thesis_title":"Kalkmyndandi l\u00edfverur \u00e1 breytilegrum b\u00fasv\u00e6\u00f0um grunn- og dj\u00fapsj\u00e1var (Calcifying organisms in changing shallow and deep marine environments)","_phd_source_url":"https:\/\/gamli.hi.is\/vidburdir\/doktorsvorn_i_jardvisindum_hronn_egilsdottir","_phd_source_node_id":"308927","_phd_source_type":"vidburdir","_phd_member_id":549,"footnotes":""},"phd_school":[113,93],"phd_discipline":[116],"class_list":["post-6116","phd_defence","type-phd_defence","status-publish","has-post-thumbnail","hentry","phd_school-jardvisindadeild","phd_school-verkfraedi-og-natturuvisindasvid","phd_discipline-phd-i-jardvisindum"],"_links":{"self":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6116","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\/6116\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media\/1940"}],"wp:attachment":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media?parent=6116"}],"wp:term":[{"taxonomy":"phd_school","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_school?post=6116"},{"taxonomy":"phd_discipline","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_discipline?post=6116"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}