Is Iceland Splitting in Half? – How Moving Tectonic Plates Impacts the Country

Iceland straddles the Mid-Atlantic Ridge where the Eurasian and North American tectonic plates meet. This unique geographical setting has led to some fascinating geological features and dynamic landscapes.In this episode, I go over the geology a little bit, the main reason why Iceland does not split in two even though the tectonic plates are slowing moving apart, and where in the country you can enjoy seeing the Mid-Atlantic Ridge in the country. The Mid-Atlantic Ridge and Iceland’s Unique Position The Mid-Atlantic Ridge is a submarine mountain range that runs down the center of the Atlantic Ocean, marking the boundary between the Eurasian and North American tectonic plates. In most places, this ridge lies deep underwater, but in Iceland, it rises above the sea, creating a rare opportunity to observe tectonic activity on land.Iceland owes its existence to this tectonic setting. The ridge is characterized by divergent boundaries, where the plates are moving away from each other. As these plates diverge, magma rises from the mantle to fill the gap, creating new crust. This process is responsible for the volcanic activity that has shaped Iceland's rugged terrain. The Nature of Tectonic Plates The movement of tectonic plates is a slow and gradual process. The Eurasian and North American plates are drifting apart at an average rate of about 2.5 centimeters (.9 inches) per year. While this may seem significant, it's important to put it in perspective. Over millions of years, this movement will indeed widen the Atlantic Ocean, but the effect on Iceland is much more subtle.The divergence of these plates does cause fissures and rift valleys, such as the Þingvellir National Park, where the rift between the plates is visible. However, this does not mean Iceland will split in half. Instead, the country is constantly being reshaped and reformed by volcanic activity and the upwelling of magma, which fills in any gaps created by the diverging plates. Volcanic Activity and Land Formation One of the key factors that prevent Iceland from splitting is its volcanic activity. Iceland is one of the most volcanically active regions in the world, with eruptions occurring roughly every four to five years. In most recent years, we have seen an increase in volcanic eruptions with them happening multiple times in a year just in 2024. These eruptions are part of the same process that forms the mid-ocean ridges.When magma from beneath the Earth's crust reaches the surface, it cools and solidifies, forming new land. This continuous creation of new crust compensates for the divergent movement of the tectonic plates. Instead of splitting apart, Iceland is actually growing larger over time as new volcanic material is added to its landmass. The Role of the Icelandic Mantle Plume Adding to the volcanic activity is the presence of the Icelandic mantle plume, a column of hot, molten rock that rises from deep within the Earth. This plume provides a steady supply of magma, which fuels Iceland's numerous volcanoes. The mantle plume is thought to be responsible for the high levels of volcanic activity and the formation of Iceland itself.The mantle plume’s upwelling helps to reinforce the island’s structure. As magma rises and cools, it forms new rock that acts to fill in and stabilize any fractures or rifts caused by the diverging plates. This process ensures that while fissures and rifts are part of Iceland’s landscape, they do not lead to the island splitting apart. Geophysical Studies and Predictions Extensive geophysical studies have been conducted to monitor Iceland's tectonic activity. Seismologists and geologists use a range of tools, including GPS measurements, seismographs, and satellite imagery, to track the movement of the plates and the activity of the mantle plume. These studies provide valuable insights into the dynamics at play.