5 research outputs found
Ecosystem approach for natural hazard mitigation of volcanic tephra in Iceland: building resilience and sustainability
Environmental changes in Northern Iceland since the Younger Dryas inferred from periglacial slope deposits
A 300-year surge history of the Drangajökull ice cap, northwest Iceland, and its maximum during the ‘Little Ice Age’
Paleomagnetism of Holocene lava flows from the Reykjanes Peninsula and the Tungnaá lava sequence (Iceland): implications for flow correlation and ages
The impact of Holocene eruptive events from hot spots like Iceland may have had significant global implications; thus, dating and knowledge of past eruptions chronology is important. However, at high-latitude volcanic islands, the paucity of soils severely limits14C dating, while the poor K content of basalts strongly restricts the use of K/Ar and Ar/Ar methods. Even tephrochronology, based on14C age determinations, refers to layers that rarely lie directly above lava flows to be dated. We report on the paleomagnetic dating of 25 sites from the Reykjanes Peninsula and the Tungnaá lava sequence of Iceland. The gathered paleomagnetic directions were compared with the available reference paleosecular variation curves of the Earth magnetic field to obtain the possible emplacement age intervals. To test the methodâ\u80\u99s validity, we sampled the precisely dated Laki (1783â\u80\u931784 AD) and Eldgjà (934â\u80\u93938 AD) lavas. The age windows obtained for these events encompass the true flow ages. For sites from the Reykjanes peninsula and the Tugnaá lava sequence, we derived multiple possible eruption events and ages. In the Reykjanes peninsula, we propose an older emplacement age (immediately following the 870 AD Iceland Settlement age) for Ogmundarhraun and Kapelluhraun lava fields. For pre-historical (older than the settlement age) Tugnaá eruptions, the method has a dating precision of 300â\u80\u93400 years which allows an increase of the detail in the chronostratigraphy and distribution of lavas in the Tugnaá sequence