A gravity survey was carried out to study the structure and geometry of craters and underlying diatremes formed in two major explosive basaltic fissure eruptions, the~60 km long AD 871±2 Vatnaöldur and AD~1477 Veiðivötn fissures in South Central Iceland, both belonging to the Bárðarbunga-Veiðivötn volcanic system.
Lýst er rannsókn á byggingu gíga og efsta hluta gosrásar í tveimur stórum tætigosum, Vatnaöldugosinu 871±2 og Veiðivatnagosinu~1477. Báðar gossprungurnar tilheyra eldstöðvakerfi Bárðarbungu.