Okmok versus the Roman republic

Okmok is a known hazard. The volcano occupies its own half of Umnak, an isolated part of the Aleutian islands. Okmok is possibly the most active of the 40-odd Aleutian volcanoes. Over the past 8600 years it has produced over 50 ash layers from separate explosions, and minor eruptions happen every other decade. AVO has…

Wrangellia: How the west was won

The Wrangell Mountains are Alaska’s most secretive volcanoes. We have looked at what they are (post I) and how they may have formed (post II). This area of Alaska has suffered the brunt of the most recent continental collision on Earth, and the Wrangell Mountains are an immense scar from this monumental accident. But there…

Building the Wrangell Mountains

The Wrangell Mountains are an unexpected treasure in a land of riches. Here are shield volcanoes higher than Mauna Loa, which have grown up over the past 5 million years. It stands alone amidst the crowd. From the Wrangell Mountains, other mountains ranges can be seen in every direction, but none of those are currently…

Wrangell Mountains

Alaska is a wonderland. The harsh winters make the land difficult to live in, and in consequence much of the wilderness seems hardly touched by human hand. No need for rewilding here – it is wild enough to begin with! Amidst the wilderness are the most majestic mountains of North America, and some of its…

Eruptions to come

Let’s start with a question. Which country do you think has the most frequent volcanic eruptions? Before you read on (or peek below for the answer), take a minute to think about it. You can probably guess that Australia is not a front runner. In fact, only two or three countries readily come to mind.…

The Anchorage earthquake of 2018

Where there are volcanoes, there are earthquakes. Both are a sign of a broken earth. Volcanoes require vertical movement and earthquakes (by and large) are horizontal: the two are not identical, but to get a volcano you need a vertical path, and to get that you need to move crust sideways. Enter the earthquakes. A…

The Bogoslof update

A year ago there were frequent eruptions of Bogoslof volcano. But over the months, it dropped out of the news, as the eruption quieted down and finally ceased. This brief post is a recoup of what came before, and what the state of the island is now. Bogoslof is one (and sometimes two or three)…

The Bogoslof eruption

Volcanoes are the tip of an iceberg. 90% of the volcano is hidden, down to the magma chamber 10 km or more below the surface. What we see is only the cone on top of the conduit. The perfect cone of Fuji, or even St Helens (before it blew up), is like the hat on…

The Aniakchak Earthquakes

Few of our readers have missed the anomalous M6.2 earthquake that occured 20 km WNW of the Aniakchak Caldera. In this article we will go through the details of the earthquake and the possible effects of the main-shock and the series of after-shocks. According to the Alaska Earthquake Center the waveform of the initial 6.2…

The Great American Volcano – Aniakchak

This is a repost of an article from October 28, 2013. The Caribou was standing on the plains 30 kilometers away from the mountain; it had not fled the roaring mountain more than that. After all, the ash was driven by the fierce wind to the north, and where it stood to the west in…