Not for nothing is Iceland known as the ‘Land of Fire and Ice.’  Its proximity to the Arctic Circle means over a tenth of its landscape is glacial.
Yet, at the same time, unique plate tectonics cause it to account for a third of all lava flows on Earth.
A divergent plate boundary known as the Mid-Atlantic Ridge runs across Iceland, separating the North American and Eurasian tectonic plates.
The plate boundary is divergent because the two plates it separates are moving away from each other at an annual rate of about 0.12 inches (3 mm).
This article will outline some of the fundamental aspects of plate tectonics in Icelandic geography and explain their consequences on the life of Icelanders.
Also, see Why Is Iceland Green and Greenland Ice? to learn more.
Iceland’s Divergent Plate Boundary
The Mid-Atlantic Ridge is a mountain range that marks the boundary between the North American and Eurasian tectonic plates.
Running from 54°S to 87°N, it is one of the longest geological features on the planet. 
However, most of it lies deep underwater at the bottom of the Atlantic Ocean, and there are only a few places where it is visible on land, one of which is Iceland.
It is considered a divergent plate boundary because the two plates it separates are moving apart – the North American plate westward and the Eurasian plate eastward.
While swift on a geological timescale, their movement is relatively slow by human standards – only about 0.12 inches (3 mm) a year.
Because the ridge runs through the center of Iceland, technically speaking, Iceland spans two continents – even though most people consider it part of Europe.
A third, less geologically influential micro-plate – the Hreppafleki plate – also runs through the island nation. 
The Effects of Plate Tectonics on Iceland’s Geology
The drifting apart of the North American and Eurasian tectonic plates makes Iceland one of the most geologically active terrains in the world.
The island has over a hundred volcanoes, with more than thirty currently active.
Iceland itself is a result of volcanic activity produced by tectonic forces.
After the two continents had drifted apart for millennia, magma from the earth’s core rushed up through volcanoes, cooled, and formed the island.
The effects of this dramatic activity are readily observable on the island.
In places like the Reykjanes Peninsula, observers can see where one continent gives way to another in a manner that is hard to witness anywhere else on the planet. 
At Thingvellir, the geological actions of 10,000 years are manifest in a rift valley that has widened by 230 ft (70 m) and sunk 131 ft (40 m), producing spectacular cliffs and an enormous lake. 
The entire island is geologically young – only between 16 and 33 million years old.
Such unique geographical features make the country a hotspot for scientists and academics looking to study the Earth’s geology.
But they also have consequences for the people who live in Iceland.
Social and Economic Consequences of Iceland’s Unique Geology
Iceland’s unique geology creates specific risks that Icelanders have learned to live with. But it also offers unique opportunities and resources that their economy benefits from.
Risks of Natural Disasters
As one of the most volcanically active zones on the planet, Iceland poses significant threats to the life and property of its citizens.
Not only do volcanoes spout burning hot lava, but they also regularly emit dust, gasses, rocks, and other chemicals.
However, most people in Iceland live away from active volcanoes. And sophisticated means of prediction mean that the government can provide advance notice of impending eruptions.
But while volcanoes rarely threaten human life anymore, violent eruptions still cause significant property damage.
Gasses and chemical elements released by eruptions can poison crops and livestock.
Likewise, volcanoes erupting under glaciers can lead to rapid flooding and cause significant property damage. This phenomenon even has an Icelandic name – Jökulhlaup. 
The most dramatic explosions can produce vast ash clouds, causing adverse effects that span continents, as in the case of a 2010 eruption that stalled flights across Europe, causing millions in losses.
A devastating eruption in 536 CE blocked the sun, plunging Europe and West Asia into darkness for 18 months.
This, in turn, caused temperatures across the region to fall and led to famine. Conditions were so dire the year has been nominated as the worst year in human history. 
Sources of Renewable Energy
But Iceland’s geology also offers many benefits and unique opportunities that have positively impacted the quality of life of people in Iceland.
Hot water from geothermal springs provides over 85% of the heating for Icelandic homes.
And hydroelectric energy caters to the remaining energy needs, making Iceland one of the few countries in the world that only relies on renewable energy sources.
Glaciers, hot springs, geysers, caves, lava fields, black sand beaches, and volcanoes are all aspects that make Iceland attractive to visitors.
From a safe distance, even active volcanoes appear magnetic.
Today, many Icelandic tour providers tap into the land’s natural beauty to offer guided tours.
Other Kinds of Plate Boundaries
Besides divergent plate boundaries, there are two other types of plate boundaries. 
The distinction between them is the direction of the movement of the two plates in each case.
As an effect of different forces, they produce specific results and geological features.
Convergent Plate Boundaries
Convergent plate boundaries are formed when two plates are moving toward each other.
The Himalaya Mountains – produced by the northward movement of the Indian continental plate into the Eurasian tectonic plate – exemplify a convergent plate boundary.
In this case, giant mountains formed as the Indian plate slipped under the Eurasian plate over many millennia.
Another consequence of this movement was the increased frequency of earthquakes in the area.
Transform Plate Boundaries
The San Andreas Fault in California resulted from the rubbing together of the Pacific and North American tectonic plates.
In this case, the plates move laterally, with the Pacific plate moving in a northwestern direction.
As with convergent plate boundaries, earthquakes are common in transform plate boundary regions.