pahoehoe lava at fagradalsfjall, iceland, with orange glow

rock geology soil boulder sand terrain formation bedrock lava flow fagradalsfjall iceland incandescent orange visible black crust green brown vegetation foreground rocks landscape orientation glow erupt heat land explore hike adventure moss 2021 active volcano background basaltic magma beautiful disaster erupting eruption geldingadalir geldingadalsgos geologist hiking hot icelandic nature mountain natural outdoor red rubble rubbly sulfur tourism trekking volcanic lobe lobes pahoehoe