{"id":3468,"date":"2021-03-26T20:38:51","date_gmt":"2021-03-26T20:38:51","guid":{"rendered":"https:\/\/elg.is\/?p=3468"},"modified":"2021-04-05T19:48:53","modified_gmt":"2021-04-05T19:48:53","slug":"gosdyngjurnar-a-reykjanesskaga-eru-risarnir-ad-vakna","status":"publish","type":"post","link":"https:\/\/elg.is\/?p=3468","title":{"rendered":"Gosdyngjurnar \u00e1 Reykjanesskaga: Eru risarnir a\u00f0 vakna?"},"content":{"rendered":"\n

Eftir \u00e1r\u00fe\u00fasunda svefn gosdyngjanna \u00e1 Reykjanesskaga er n\u00fd a\u00f0 f\u00e6\u00f0ast \u00ed Geldingadal.<\/p>\n\n\n\n

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N\u00fd gosdyngja, s\u00fa fyrsta \u00ed sj\u00f6 \u00fe\u00fasund \u00e1r, vir\u00f0ist vera a\u00f0 f\u00e6\u00f0ast \u00e1 Reykjanesskaga samkv\u00e6mt \u00fev\u00ed sem jar\u00f0v\u00edsindamenn telja.  Efnasamsetning kvikunnar sem kemur upp \u00ed Geldingadal gefur til kynna a\u00f0 h\u00fan komi dj\u00fapt \u00far i\u00f0rum jar\u00f0ar en einmitt \u00fea\u00f0 einkennir dyngjugos. \u00deetta eru afar merkilegt t\u00ed\u00f0indi, svo ekki s\u00e9 meira sagt. Reykjanesskaginn hefur a\u00f0 geyma nokkrar myndarlegar gosdyngjur en \u00fe\u00e6r hafa ekki veri\u00f0 virkar \u00ed \u00e1r\u00fe\u00fasundir og \u00fev\u00ed kemur gosi\u00f0 \u00ed Geldingadal \u00e1 \u00f3vart. \u00c1 skaganum eru taldar 25 gosdyngjur og \u00ed \u00feessum pistli er fjalla\u00f0 um \u00fe\u00e6r helstu.<\/strong><\/p>\n\n\n\n

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Gosdyngjurnar, hinir fornu risar eldvirkninnar \u00e1 Reykjanesskaga, voru upp \u00e1 sitt besta um \u00fea\u00f0 leyti sem \u00edsaldarj\u00f6klarnir voru a\u00f0 sleppa hr\u00f6mmum s\u00ednum af landinu fyrir um 10-12 \u00fe\u00fasund \u00e1rum. Dyngjunar m\u00f3tu\u00f0u landslag skagans fyrstu \u00e1r\u00fe\u00fasundin eftir \u00fea\u00f0 en fyrir um \u00fea\u00f0 bil 6-7 \u00fe\u00fasund \u00e1rum breyttist  gosvirknin \u00feegar sprungugosin t\u00f3ku vi\u00f0 og dyngjurnar l\u00f6g\u00f0ust \u00ed dvala. \u00de\u00e6r eru samt sem \u00e1\u00f0ur <\/p>\n<\/div>\n\n\n\n

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innan hins virka gosbeltis og \u00ed \u00feeim skilningi ekki \u00fatkulna\u00f0ar eins og hinar fornu megineldst\u00f6\u00f0var sem reki\u00f0 hefur \u00fat \u00far gosbeltunum \u00ed millj\u00f3na \u00e1ra landreki. E\u00f0lismunur \u00e1 \u00feessum tveimur ger\u00f0um eldst\u00f6\u00f0va er l\u00edka mikill. \u00dea\u00f0 sem einkennir dyngjugosin er a\u00f0 kvikan kemur beina lei\u00f0 upp \u00far m\u00f6ttlinum en safnast ekki fyrst \u00ed kvikuh\u00f3lfi eins og \u00ed \u00f6\u00f0rum eldst\u00f6\u00f0vum.<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n

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\u00cd dyngjugosum kemur kvikan beint upp af miklu d\u00fdpi. \u00cd Geldingadal er tali\u00f0 a\u00f0 \u00fea\u00f0 s\u00e9 17-20 k\u00edl\u00f3metrar. Kvikan er \u00fe\u00e1 \u00far basalti. \u00cd annars konar eldst\u00f6\u00f0vum safnast kvikan fyrst fyrir \u00ed kviku\u00fer\u00f3 \u00e1\u00f0ur en h\u00fan finnur s\u00e9r lei\u00f0 upp \u00e1 yfirbor\u00f0. \u00dev\u00ed lengur sem h\u00fan mallar \u00ed kvikuh\u00f3lfinu, \u00fev\u00ed \u00fer\u00f3ari ver\u00f0ur h\u00fan og kemur \u00fe\u00e1 upp t.d. sem l\u00edpar\u00edt \u00ed megineldst\u00f6\u00f0vum e\u00f0a s\u00fart berg.<\/strong><\/p>\n\n\n\n

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Tv\u00e6r st\u00e6rstu dyngjurnar \u00e1 vestanver\u00f0um skaganum eru Su\u00f0urnesjadyngjurnar \u00der\u00e1insskj\u00f6ldur og Sandfellsh\u00e6\u00f0<\/strong>.  Fr\u00e1 \u00feeim rann gr\u00ed\u00f0arlegt hraunmagn enda standa dyngjugosin oftast yfir \u00ed langan t\u00edma. \u00c1 Hawaii st\u00f3\u00f0 eitt sl\u00edkt yfir n\u00e1nast samfleytt fr\u00e1 \u00e1rinu 1983 \u00fear til \u00ed desember 2018 \u00feegar gosinu var formlega l\u00fdst loki\u00f0 eftir a\u00f0 eldst\u00f6\u00f0in haf\u00f0i ekki veri\u00f0 gosvirk \u00ed 90 daga.  K\u012blauea dyngjan \u00e1 s\u00e9r samt mun lengri s\u00f6gu, talin vera h\u00e1tt \u00ed 300 \u00fe\u00fasund \u00e1ra g\u00f6mul og gosi\u00f0 margoft. Eldst\u00f6\u00f0var af \u00feessari ger\u00f0 taka s\u00e9r stundum p\u00e1su \u00ed einhvern t\u00edma og \u00feegar gos hefst \u00e1 a\u00f0 n\u00fdju ver\u00f0ur gjarnan tilf\u00e6rsla \u00e1 gosopinu. \u00dear sem Geldingardalur er ekki svo \u00fdkja <\/p>\n<\/div>\n\n\n\n

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langt fr\u00e1 hinum fornu gosg\u00edgum \u00der\u00e1insskjaldar m\u00e6tti kannski gera s\u00e9r \u00ed hugarlund a\u00f0 hann v\u00e6ri a\u00f0 vakna af l\u00f6ngum dvala. \u00dea\u00f0 er \u00fe\u00f3 h\u00e6pi\u00f0 \u00fear sem langt er um li\u00f0i\u00f0 s\u00ed\u00f0an gaus s\u00ed\u00f0ast \u00e1 \u00feessum sl\u00f3\u00f0um og ekki um s\u00f6mu goshrinu a\u00f0 r\u00e6\u00f0a. Allavega er kvikan sem kemur upp \u00ed Geldingadal a\u00f0 efnissamsetningu mj\u00f6g svipu\u00f0 a\u00f0 ger\u00f0 og \u00feau hraun sem \u00der\u00e1insskj\u00f6ldur og Sandfell framleiddu (\u00d3liv\u00edn\u00fe\u00f3lei\u00edt). Eldst\u00f6\u00f0var af dyngjuger\u00f0 geta framleitt gr\u00ed\u00f0arlegt hraunmagn og m\u00e1 \u00ed \u00fev\u00ed sambandi nefna a\u00f0 \u00e1ri\u00f0 2016 \u00feakti hrauni\u00f0 \u00far yfirstandandi goshrinu K\u012blauea 144 ferk\u00edl\u00f3metra lands, sem er svipa\u00f0 og hraunin \u00far Sandfellsh\u00e6\u00f0 \u00feekja.<\/p>\n<\/div>\n<\/div>\n\n\n\n

\u00der\u00e1insskj\u00f6ldur og Sandfell:<\/strong>
\u00c1 jar\u00f0fr\u00e6\u00f0ikorti fr\u00e1 Isor h\u00e9r a\u00f0 ne\u00f0an s\u00e9st vel hversu v\u00ed\u00f0\u00e1ttumikil hraunin eru sem runni\u00f0 hafa  fr\u00e1 \u00feessum tveimur dyngjum. Korti\u00f0 s\u00fdnir \u00fe\u00f3 eing\u00f6ngu sj\u00e1anlegt hraun \u00e1 yfirbor\u00f0i en yngri hraun hafa runni\u00f0 yfir \u00feau g\u00f6mlu og fyllt upp dali og d\u00e6ldir \u00e1 milli dyngjanna.<\/p>\n\n\n\n