Iceland - 12 - Fire 1 - Volcanoes and Lava

11-15 August,  23 August - 4 September, 2025

Iceland is frequently described as "Fire and Ice", so now I'm coming to the fire portion - all stemming from Iceland's position along the mid-Atlantic rift that at the moment (geologically speaking) also sits upon a mantle plume or "hot spot". (Other notable hot spots are Hawaii, the Galapagos, and Yellowstone.)

Volcanoes

11 August

Hekla on a rare day when the top isn't shrouded in clouds. Hekla is one of Iceland's most active volcanoes, with 20 eruptions since 1210.

13 August

A more typical day for Hekla.

11 August

Eyjafjallajökull - the volcano that erupted in 2010 and shut down air travel in northern and western Europe for about a week.

Lava Fields and Flows

13 August

The massive ice cap Vatnajökull appears in the distance behind the Eldhraun lava field. Eldhraun emerged from the Laki Craters in the Highlands during an eruption in 1783-1784. Covering around 565 km², it is one of the largest lava fields in the world.

13 August

Old vents leave cones in a lava field.

15 August

Recent lava flow in Grindavík on the Reykanes peninsula. The Sundhnúkur eruptions started in 2023, and the most recent one ended in August 2025, just a week before we arrived in Iceland.

Lava flowed over a highway, which was rebuilt next to it.

Lava flows are very jagged and hazardous.

Raufarhólshellir Lava Tunnel

As the surface of a new lava flow cools, hot, molten lava continues to flow underneath. After the lava flow stops, it can leave behind subterranean lava tubes, also called lava caves or lava tunnels. We've been in lava tubes in Hawaii and the Galapagos. The Raufarhólshellir lava flow is about 5600 years old.

The sides of the lava tube look like they are wet and have been shaped by water, but these drips are not stalactites, these are the drips of lava as it cooled.

Grooves ("bathtub rings") were formed by different levels of lava flowing through the tube.

Going deeper into the cave.

From time to time a thin spot in the roof can collapse to form a "skylight".

Dimmuborgir

Dimmuborgir is a lava field that was formed about 2300 years ago when a crusted-over lava lake drained and the roof collapsed, leaving a fairy land of grotesque and fanciful lava shapes.

29 August

Lava cliffs

Presumably, the lava solidified around steam bubbles that formed when groundwater and lava connected.

Kirkja - the "church".

Lava is like clouds - everyone sees something in the shapes. Are these trolls who did not get back underground by sunrise and turned to stone?