Postglacial volcanism in Iceland

摘要: Iceland is one of the most active and productive terrestrialvolcanic regions, with eruption frequency �20 events per century magma output rates of�5 km 3 century. Although dominated by mafic magmatism volcanism, as evident from 91:6:3 dist ribution mafic, intermediate silicic erup- tions, its record also features common terrestrial mag ma types styles. Postglacial volcanism confined to neovolcanic zones where 30 volcanicsystems are responsible for Holocene activity. On basis our current post-glacial eruptiondata set we estimate that Icelandic has produced around 2400 eruptions about 566±100 erupted in last 11 ka. Effusive activ- ity accounts for�500 eruptions; remainder explosive dictated su bglacial (�77%), demonstrating strong environmental influence on s Iceland. In terms large volume (>1 ) effusive eruptions. About 50 such have occu rred throughout postglacial time or�2% total number However, collectively t hese pro- duced 55% volume. The Eastern Volcanic Zone >80% and�60% been far pro lific producer among zones. Furthermore, effu sive not evenly distributed through time, because only 30% (111 was 5 ka re- maining 70% ( 258 between 5-11 production rate millenni a within these two periods appears be fairly even, ranging 20-30 <5 period 35-40 5-10 interval. exception 10-11 interval, when�70 lava formed activity or close double millennia f ollowed.