#underwater

Upward Spiral

/ PK Read / Leave a comment

A new study published  in Nature by Harvard University researchers corrects a few measurements when it comes to changes in the sea level over the past century.

On the one hand, researchers wanted to gain a more accurate picture of how quickly sea levels are actually rising in an era of global warming.

Blue Garden, 200 meters beneath the ocean surface. The top of the sphere could be elevated above the surface for sunlight and fresh air, and retracted during storms. Image: Shimizu Corporation

Blue Garden, 200 meters beneath the ocean surface. The top of the sphere could be elevated above the surface for sunlight and fresh air, and retracted during storms.
Image: Shimizu Corporation

On the other hand, they re-examined assumptions on the speed of sea level change over the past century by re-assessing data and ‘fingerprints’ used to measure the change in sea levels between 1900-1990.

Current predictive models for how quickly glacial melting will impact coastlines are based on analyses of past sea levels showing a gradual rise over many decades.

What the research team under Carling Hay and Eric Morrow found upon re-examining data gathered over the course of the 20th century was that sea levels had risen much less than previously thought, in some cases up to 30% less, by 1990.

Which means that the current rising levels didn’t happen slowly over the course of a long century – they have occurred much more quickly over the past twenty years due to a wide variety of factors.

This may require some adjustments to coastal planning.

Good thing Japan’s Shimizu Corporation just released these drafts for an underwater town, poetically dubbed ‘Blue Garden‘.

Blue Garden, interior view. The sphere would contain homes, stores, offices, a hotel and research facilities. Image: Shimizu Corporation

Blue Garden, interior view. The sphere would contain homes, stores, offices, a hotel and research facilities.
Image: Shimizu Corporation

The proposed city would be sustainable and energy self-sufficient using thermal power generated by temperature differences between the water surface and ocean depths, as well as from methane-producing micro-organism factories.

The Corporation says it could produce the spherical abodes, which would be attached to the ocean floor and could accommodate up to 5000 people, by 2030.

The Blue Garden spheres could be connected into networks of spheres to create cities. Image: Shimizu Corporation

The Blue Garden spheres could be connected into networks of spheres to create cities.
Image: Shimizu Corporation

Submerged Lines

/ PK Read / Leave a comment

We humans are visual creatures. It’s in our nature to focus on what we can see, it’s in our nightmares to focus on the unseen and the hidden because we just aren’t very good at preparing ourselves for what isn’t readily visible. Even within our own bodies, some of the most dangerous illnesses are the ones with few symptoms – at least until they suddenly erupt. High blood pressure seems like no big deal until a stroke hits.

Somehow, we manage to have the same approach to pathways and passages which we ourselves have built. Like forgetful squirrels, we lay pipelines for oil and gas supplies, assume the supply will remain intact, and then put them out of our minds.

Pipelines to carry oil have been laid all around the world for a century. And like any pipe, at some point they show their signs of age. Pipes can break due to corrosion, excavation work, material and welding errors, natural force, external damage (such as anchors hitting underwater pipes), and faulty operation.

Mostly, though, it’s age and material failure that cause leaks like the recent Tioga leak in North Dakota, the largest U.S. onshore spill in history. A quick glance here will reveal an unsettling, ongoing litany of oil spills during any given month.

Lakehead System Source: Enbridge

Lakehead System
Source: Enbridge

In Michigan, two 50 cm (20 in.) pipes were laid down in 1953 as a part of the 3000 km (1900 m.) Lakehead System that runs from North Dakota down to points east and south. Most of the Lakehead system is underground, this segment, known as Line 5, runs underwater through the Straits of Mackinac between northern Wisconsin and Michigan’s Upper Peninsula.

The pipes traverse the juncture between two Great Lakes, Lake Michigan and Lake Huron. “While Line 5’s capacity has increased, neither regulatory scrutiny nor corporate transparency have followed suit. The Great Lakes, which contain 84% of North America’s and 20% of the planet’s surface freshwater, are at a greater risk than ever,” according to FLOW, a non-profit organization working to protect the Great Lakes.

This map produced by the National Wildlife Federation estimates the extent to which oil might flow from a pipeline rupture beneath the Straits of Mackinac. Source: NWF

This map produced by the National Wildlife Federation estimates the extent to which oil might flow from a pipeline rupture beneath the Straits of Mackinac.
Source: NWF

Line 5 is owned and operated by Enbridge Energy Partners LP, a company that insists the lines have been operating well for ‘decades’ and are perfectly intact. This is the same company whose lines burst and polluted the Kalamazoo River at a continuing clean-up cost of four years and over $1 billion.

Sometimes, the unseen around which we build our nightmares doesn’t merit closer examination; it’s just smoke and ephemera, the stuff of tall stories.

This probably isn’t one of those cases.

Straits of Mackinac Source: FLOW

Straits of Mackinac
Source: FLOW

Seabed Data

/ PK Read / Leave a comment

The first trans-Atlantic communications cable was laid in 1858, carried across the ocean by two ships and connected to create instantaneous communication across an ocean.

Unfortunately, it only worked for few days, and it was almost ten years before a replacement was successfully laid. That cable, however, remained in service for a century.

I only mention that because I came across this global map of submarine communications cables. A cartography of big data streams at the bottom of the sea.

Submarine Cable Map (2014) Source: TeleGeography Click on the map for the interactive version

Submarine Cable Map (2014)
Source: TeleGeography
Click on the map for the interactive version

It all looks so tidy and reassuringly mechanical on a map like this.

Still, each and every festively colored line represents something like this:Power-Submarine-Cable-1

That was laid like this:13120_540

Some of the cables, like those that cross the Izu-Ogasawara Trench off Japan, rest at 8000 meters (26,000 ft), a depth that almost equals the height of Mt. Everest. At some point, most of them must end up looking like some version of  this:image010

The nuts and bolts of the modern world are subject to breakage, mostly due to either environmental forces (volcanic eruptions, earthquakes, storms) or human activity (mostly fishing lines, mining operations or dropped anchors).

Given the lack of knowledge of the Atlantic sea bed in the 19th century, it’s all the more impressive that the first successful cable last 100 years.

Seabed profiles. Source: Telegeography

Seabed profiles.
Source: Telegeography