Creeping Landslides Endanger Critical Alaskan Infrastructure
Written on
Chapter 1: The Zombie Landslide Phenomenon
In Alaska, a peculiar yet alarming story unfolds: a slow-moving, underground landslide—often dubbed a "zombie landslide"—is posing a significant risk to a vital highway. Recent data indicates that temperatures in Alaska are rising at a rate faster than in many other parts of the world, exacerbating concerns regarding climate change in the Arctic. One of the unexpected outcomes of this warming trend is the activation of these previously dormant landslides, which now jeopardize essential economic infrastructure.
The Dalton Highway, a crucial 414-mile route linking Fairbanks to Prudhoe Bay, is currently being impacted by these flows. While the term "tearing through" suggests rapid movement, these debris flows progress at a mere 20 to 30 feet annually. However, it’s noteworthy that fifty years ago, they were completely stationary, locked in place by permafrost. Engineers initially deemed them non-threatening, but global warming has since resurrected these flows.
Comprising a mix of sand, gravel, rocks, and trees, these flows are now becoming increasingly mobile as the permafrost melts. One notable flow, referred to as "Lobe A," measures approximately 4,000 feet in length, 600 feet in width, and 65 feet in depth. In 2013, it moved at a rate of about 16 feet per year, but by 2020, this pace had doubled. To mitigate the risks, engineers have recently adjusted the highway's route slightly to the west, buying time but not solving the underlying issue.
Section 1.1: Understanding the Broader Context
The situation extends beyond a single landslide. The State Highway Department has identified 43 distinct debris flow lobes along the Dalton Highway. These features originated thousands of years ago, following the last ice age, when glacial movements carved out depressions in the bedrock. As the glaciers retreated, these hollows gradually filled with debris, which was initially secured by the permafrost. However, as temperatures rise and permafrost thaws, these debris lobes are now shifting downhill under the force of gravity.
Even as recently as the early 1970s, these deposits were solid and immobile, posing no risk to either the highway or the oil pipeline that runs parallel to it, transporting crude oil from Prudhoe Bay to refineries. At that time, the concept of climate change was not fully understood, and the implications of fossil fuel consumption were underestimated.
With advancements in scientific understanding, it has become clear that rising temperatures are accelerating permafrost melt, which, in turn, increases the movement of these debris lobes.
Subsection 1.1.1: The Irony of Climate Change
Alaska's oil producers now find themselves in a paradox. The fossil fuels they have extracted and utilized for decades have significantly contributed to climate change. The greenhouse gases emitted during combustion have raised global temperatures, causing Alaska's climate to warm at a rate three times faster than the global average.
The trans-Alaska Pipeline, a key infrastructure built in 1974, runs alongside the Dalton Highway, making it vulnerable to the encroaching landslides. While the highway is the first target, the pipeline is also at risk from these slow-moving flows.
In a dramatic twist, the heat generated by oil extraction in the North Slope has catalyzed the reawakening of these underground debris flows, now threatening to disrupt the pipeline's operation. The consequences of our actions are becoming increasingly apparent, as these flows are a direct byproduct of global climate change.
The Dalton Highway is essential for connecting remote Arctic communities and facilitating the supply chain to the North Slope oil fields. With the pipeline transporting around 20 million gallons of crude oil daily, the loss of both the highway and the pipeline would severely impact Alaska's economy. What was once dismissed as an exaggerated concern has become a pressing issue, with no clear resolution in sight.
Chapter 2: The Dangers Ahead
This video showcases the harrowing experience of cruise passengers stranded due to a landslide, illustrating the immediate dangers posed by such geological events.
This report highlights the tragic outcome of a landslide that swept through roads and homes in Alaska, underscoring the urgent need for awareness and action regarding these environmental threats.
The EarthSphere Blog: A platform for exploring life and our planet.