Gaia Diary

Navigable aqueducts (sometimes called water bridges) are bridge structures that carry navigable waterway canals over other rivers, valleys, railways or roads. They are primarily distinguished by their size, carrying a larger cross-section of water than most water-supply aqueducts. Although Roman aqueducts were sometimes used for transport, aqueducts were not generally used until the 17th century when the problems of summit level canals had been solved and modern canal systems started to appear.

Where Earth has been changed forever.

If you had any doubts that we're living in a new age called the Anthropocene – the term geologists have begun to use to describe our era, as defined by the impact humans are leaving on the planet – then a look at the hundreds of cavernous open-pit mining operations scattered across the Earth's surface ought to be convincing.

But human hands haven't been the only ones scoring the planet's face. Massive meteors have punctured our atmosphere many times in the past, leaving behind craters more than a dozen miles wide in some cases.

We took a look at some of the biggest holes in the ground and craters around the planet, and in the process unearthed some fascinating places.

Marine species threatened with extinction aren't just whales, seals and turtles--they include fish, corals, mollusks, birds, and a lone seagrass

Fossil evidence of the earliest monkey and Old World ape has been found in the East African Rift Valley.

Yes it’s a tiny creature that spends most of its life time floating upside down in the deep blue water of the Atlantic, Indian and Pacific Ocean. What keeps it floating on the surface of the water is the air bubble that it fills in its belly, whichever way the wind blows it takes this little creature along with it, so all it does is relax while floating in the water. Can you imagine a more carefree life than Glaucus Atlanticus?

The chemistry of the ocean is changing. Most climate change discussion focuses on the warmth of the air, but around one-quarter of the carbon dioxide we release into the atmosphere dissolves into the ocean.

Dissolved carbon dioxide makes seawater more acidic—a process called ocean acidification—and its effects have already been observed: the shells of sea butterflies, also known as pteropods, have begun dissolving in the Antarctic.

Tiny sea butterflies are related to snails, but use their muscular foot to swim in the water instead of creep along a surface. Many species have thin, hard shells made of calcium carbonate that are especially sensitive to changes in the ocean’s acidity.

Their sensitivity and cosmopolitan nature make them an alluring study group for scientists who want to better understand how acidification will affect ocean organisms. But some pteropod species are proving to do just fine in more acidic water, while others have shells that dissolve quickly. So why do some species perish while others thrive?

Intense heat from lava entering seawater initiates a chemical reaction between salt ions dissolved in seawater and water which results in hydrochloric acid (HCl). Geologists love to carry small bottles filled with this substance because it makes a great tool for testing carbonate rocks. Actually, we all carry it along because this is the acid that fills our stomachs. It is diluted, though, but so are acid in geologist’s bottles and also the cloud you see on the picture below.

(Reuters) - Conservationists are criticizing a plan by wildlife managers in Montana that would nearly double the number of wolves a person is allowed to kill each year, lengthen the hunting season and sanction shooting of wolves near baited traps.

What do grizzly bears in Yellowstone National Park eat? Comedians are likely to answer: Whatever they want. But what they want—native Yellowstone cutthroat trout—are struggling, thanks to the illegal introduction of non-native lake trout in the 1980s by fishers. The bigger lake trout have been feasting on the cutthroat variety, and now there simply aren't enough of the latter for the bears, which dine on the cutthroats when they spawn in shallow waters. The lake trout don't provide an alternative food source, because they spawn at depths that are inaccessible to the bears. So, the grizzlies have increasingly turned to a different, but equally nutritious prey item: elk calves.

Atlas Obscura on Slate is a new travel blog. Like us on Facebook, Tumblr, or follow us on Twitter @atlasobscura The eroded remnants of a shield volcano, Ball's Pyramid thrusts upward 1,843 feet out of the South Pacific.

Analyses of ancient rocks suggests that Earth's tectonic activity was at its most boistrous 1. 1 billion years ago and has been settling down ever since

The SS Ayrfield is one of many decommissioned ships in the Homebush Bay, just west of Sydney, but what separates it from the other stranded vessels is the incredible foliage that adorns the rusted hull. The beautiful spectacle, also referred to as The Floating Forest, adds a bit of life to the area, which happens to be a sort of ship graveyard.

People choose to live in some pretty baffling places, like those towns sitting at the base of volcanos or the precariously placed monasteries in the Himalayan mountains.

Smithsonian scientists are gathering wildlife tissue samples from around the world to build the largest museum-based repository of such specimens

The cap of floating sea ice that covers the Arctic Ocean melted in the summer of 2012 to its smallest size in nearly 35 years of satellite observations.

But as frigid fall and winter temperatures swept over the region, the Arctic seas refroze and the dynamic mass of ice grew again toward its annual peak, reaching it on February 28, 2013.

These two seasonal milestones—the Arctic sea ice minimum and maximum—are closely watched by NASA scientists and used as benchmarks of climate change.

While the drastic shrinking of the minimum has gained attention in recent years, the maximum has also declined in size but at a slower rate. Still, nine of the 10 smallest maximums in the satellite era occurred in the past decade, with the 2013 maximum ranking as the fifth smallest since 1978.

Watch the visualization to see satellite observations of Arctic sea ice from March 2012 through February 2013.

When spring is in the air everyone looks forward to meet the beautiful and eye pleasing flowers and plants. So today we have some amazing plants for you that you may have not seen or heard of before.

The three different formations of South Pacific coral-reef islands have long fascinated geologists. Tahiti's coral forms a 'fringing' reef, a shelf growing close to the island's shore.

Troglodytes who couldn't compete, or humans with complex culture?

Among the oldest human objects that unequivocally defy practical explanations are shells punctured with holes. Try as you might, it’s hard to see them as anything other than beads or pendants. Traces of ochre at sites occupied by ancient humans offer earlier hints of adornment, perhaps even of symbolism, but sceptics argue that the pigment might have been used for some practical purpose: tanning hides, for instance. In perforated seashells, however, we find the first truly compelling tokens of expressive humanity.

Early humans must have reached beyond their immediate concerns in many ways that have left no traces. But they did reach for shells very early. Some 75,000 years ago in southern Africa, they gathered and pierced them, perhaps to make bracelets or necklaces. Twenty-five thousand years later and nearly 10,000km away, in what is now southern Spain, others collected naturally perforated shells. Independently and far removed from each other, humans took similar paths into expressive culture. What does that tell us about the human mind?

According to a new US Geological Survey (USGS) study, nesting green sea turtles are benefiting from marine protected areas by using habitats found within their boundaries. This study is the first to track the federally protected turtles in Dry Tortugas National Park.

In Florida, the green sea turtles are listed as an endangered species, while in the rest of their range they are considered threatened. The habits of these turtles after their forays to nest on beaches in the Southeast US have long remained a mystery. Scientists didn’t know if the turtles made use of existing protected areas until now, and few details were available as to whether these areas were suited to supporting the green sea turtle’s survival.

This is the incredible moment a fierce lightning bolt crashed against the Grand Canyon.

Stargazers converged on a remote hill in Central Australia to view a spectacular annular eclipse.