It is final day of the Round of 32. Check out the full bracket here.

You can still vote for Day 1, Day 2 and Day 3 as well!

Match 13: Argentina v. Spain

Argentina: 0.05% (23,700) live within 30 kilometers of a Holocene volcano; 1.5% (618,000) live within 100 kilometers of a Holocene volcano.

Thanks to the geography of Argentina, there is a surprisingly low percentage of the population that actually lives within 100 kilometers of a Holocene volcano. However, that doesn’t spare Argentina from hazards. The prevailing winds will send ash from the Chilean border region to the east, so even eruptions wholly in Chile can dump large amounts of ash onto Argentina. The ash and pumice from the Puyehue-Cordon Caulle eruption in 2011 piled up in Argentina with tens of centimeters of volcanic debris. All that ash and pumice will contaminate water supplies, ruin crops and trees, make it hard to breathe and ground flights.

Spain (Mainland): 3.7% (1.73 million) live within 30 kilometers of a Holocene volcano. 16.2% (7.57 million) live within 100 kilometers of a Holocene volcano. (Canaries): 100% (2.1 million) live within 100 kilometers of a Holocene volcano.

I talked about the volcanoes of the Canary Islands for the group phase but Spain does have its own volcanoes on mainland Europe. In fact, more than 10 times as many people live near a Holocene volcano in Spain than in Argentina even ignoring the Canaries. Of course, it has been over 5,000 years since that last eruption in mainland Spain at the Calatrava Volcanic Field. This volcanic field covers 5,000 square kilometers and has mostly produced lava flows and cinder cones. We are more uncertain about the last eruption of the Olot Volcanic Field, but it is only 90 kilometers from Barcelona.

Match 14: USA v. Iran

USA: 0.12% (388,000) live within 30 kilometers of a Holocene volcano; 1.4% (4.2 million) live within 100 kilometers of a Holocene volcano.

I’ve been dreading this potential matchup for obvious reasons. I am going to put geopolitics aside as best as I can. The US is well deserving to win a Volcano World Cup. The Aleutians are one of the longest chains of volcanoes on the planet, running conservatively over 2,600 kilometers from Buldir in the west to Hayes in the east. The Aleutians have more volcanoes than most countries and then the US can add Hawaii, the Cascades, Yellowstone, Long Valley and more. You could argue it has the most variety of volcanism of any country on Earth and likely it is not even close.

Iran: 0.47% (366,000) live within 30 kilometers of a Holocene volcano; 25.7% (20 million) live within 100 kilometers of a Holocene volcano.

With the multitude of earthquakes that hit Iran, most people neglect the volcanic hazards that are present. Damavand does have some hotsprings and fumarole (hot gas) vents showing the persistent heat beneath the volcano. One of the weirder volcanoes in Iran is Taftan where a potential eruption in 1993 may have actually been a molten sulfur flow related to the hydrothermal system at the volcano. However, the youngest dated lava flows are almost 700,000 years old! We really just don’t know much about the volcanism of Iran.

Match 15: Canada v. Sweden

Canada: 0.11% (375,000) live within 30 kilometers of a Holocene volcano; 1.22% (4.19 million) live within 100 kilometers of a Holocene volcano.

Although the volcanoes of the northern Cascades are likely the best known Canadian volcanoes, some of the more recent eruptions weren’t from Garibaldi or Meager. The Iskut-Unuk River Cones near Alaska erupted in 1800. The Tseax River Cone, also near the Alaska border, erupted in 1690. The Wells Gray-Clearwater complex, in eastern British Columbia almost in Saskatchewan, erupted in 1550. All of these are fairly small volcanic centers that made lava flows and cones, but still, a new Canadian lava field would be exciting.

Sweden: 0% live within 100 kilometers of a Holocene volcano.

There are no volcanoes in Sweden today, but they do lie well within the path of eruptions from Iceland. I ran across a study that looked at what would happen to Sweden if an eruption on the scale of Laki (1783-84) occurred. That Laki eruption was one of the largest lava flow eruptions in human history and the gas emissions caused widespread atmospheric and meteorological impacts to Europe. The biggest hazard would be the increased sulfur dioxide emissions that would impact human health even in Sweden across the North Atlantic. They might not have volcanoes, but volcanic hazards are still a potential.

Match 16: DR Congo v. Senegal

DR Congo: 3% (2.03 million) live within 30 kilometers of a Holocene volcano; 12% (8.3 million) live within 100 kilometers of a Holocene volcano.

Although it likely hasn’t erupted in a few thousand years, Karisimbi is still considered one of the potentially active volcanoes of the Democratic Republic of the Congo. I did one of my short-lived 5 Minute Volcano podcast episodes on Karisimbi and it is more magmatically complex than its cousins Nyiragongo and Nyamulagira. Karisimbi lava flows and vents make it down all the way to Lake Kivu. As I mention in the podcast, Karisimbi can still be deadly as rainfall remobilized volcanic debris into lahars in 2010 that killed at least 50 deaths.

Senegal: 0% live within 100 kilometers of a Holocene volcano.

The Falémé Volcanic Belt in Senegal may be old — likely over 1.5 billion years old — but it still is important to Senegal. Much of the gold exploration in the west African nation falls in this region. Many ancient volcanic areas are rich in gold, copper, silver and many more metals. This means ancient volcanoes can leave a long shadow billions of years into the future thanks to all the material they can bring from the planet’s interior.