Nemo Peak appears to be the source of several tephra layers found in the Sea of Okhotsk named K2 and K3. These tephras extend up to away from Onekotan Island but their locations do not overlap: K2 tephras extend northwestward away from Onekotan and pyroxenes crystallized under different conditions. The volume of the K2 tephra has been estimated at around . This tephra is of rhyolitic composition.