<P> Radiocarbon dating has established that Mount Tambora had erupted three times during the current Holocene Epoch before the 1815 eruption , but the magnitudes of these eruptions are unknown . Their estimated dates are 3910 BC ± 200 years , 3050 BC and 740 AD ± 150 years . An earlier caldera was filled with lava flows starting from 43,000 years BP ; two pyroclastic eruptions occurred later and formed the Black Sands and Brown Tuff formations , the last of which was emplaced between about 3890 BC and 800 AD . </P>
<P> Radiocarbon dating has established that Mount Tambora had erupted three times during the current Holocene Epoch before the 1815 eruption , but the magnitudes of these eruptions are unknown . Their estimated dates are 3910 BC ± 200 years , 3050 BC and 740 AD ± 150 years . An earlier caldera was filled with lava flows starting from 43,000 years BP ; two pyroclastic eruptions occurred later and formed the Black Sands and Brown Tuff formations , the last of which was emplaced between about 3890 BC and 800 AD . </P>
when was the first time mount tambora erupted
when was the first time mount tambora erupted
3910 BC ± 200 years
3910 BC ± 200 years