NASA's Earth Observatory has posted some incredible photos of the vanishing Aral Sea. The lake, tucked between Kazakhstan and Uzbekistan, was once the fourth-largest in the world. Today, after decades of being drained for irrigation, it's nearly gone.

And the lake hit a new low in August of this year: "For the first time in modern history," NASA notes, "the eastern basin of the South Aral Sea has completely dried." Here's a comparison between 2000 and 2014:

The Aral Sea: August 2000 (left) vs August 2014 (right)

(NASA Earth Observatory)

Note that even the somewhat bigger lake back in 2000 was just a shell of what it was in the 1960s, as the historical photograph below suggests:

The Aral Sea in 1964

(NASA Earth Observatory)

So what happened? Historically, the Aral Sea was fed by both the Syr Darya and the Amu Darya rivers flowing down from the mountains. But in the 1960s, the Soviet Union diverted both rivers — through a network of dams and canals — for use in cotton fields and other agriculture.

'Although irrigation made the desert bloom, it devastated the Aral Sea'

Here's NASA: "Although irrigation made the desert bloom, it devastated the Aral Sea. As the lake dried up, fisheries and the communities that depended on them collapsed. The increasingly salty water became polluted with fertilizer and pesticides. Blowing, salty dust from the exposed lakebed became a public health hazard and degraded the soil. Croplands had to be flushed with larger and larger volumes of river water."

By the 2000s, the Aral Sea was roughly 10 percent of its original size. The area's once-vital fishing industry had been completely eradicated, leaving entire communities unemployed. The disappearance of the sea has also affected the local climate — summers have been getting hotter, and winters have been getting colder.

And now the lake keeps shrinking during dry years. In 2014, a paucity of snow in the mountains combined with continued high levels of water withdrawals for irrigation helped dry out the eastern basin for the first time in possibly 600 years, explained Philip Micklin, a geographer emeritus from Western Michigan University.

Of course, the lake tends to ebb and grow with wet and dry seasons. As you can see in NASA's photos, the eastern side of the lake had nearly gone dry in 2009 but then returned in 2010. Meanwhile, there are some projects to try to save the deeper western basin of the Aral Sea from vanishing entirely. But it's unlikely the lake will ever return to what it was before the 1950s.