Taxonomy term

delta

Travels in Geology: Tracking African animals and deranged drainages across the Kalahari

The Okavango Delta, a major river delta in the middle of the dry Kalahari, and thundering Victoria Falls, a day’s drive away, may seem unrelated. But to a geologist, they are inextricably linked by hydrologic changes that have swept across southern Africa in response to subtle tectonic movements and major Pleistocene climate fluctuations.
12 Jun 2017

Measuring rising seas is tricky in deltas

Earth’s stratigraphic record offers a patchwork diary of how different parts of the planet have formed and changed over time. Some of the most extensive pieces of the stratigraphic record are found in deltas, making them ideal places to look for long-term chronicles of Earth’s history, as well as clues to future changes to our coastal landscapes.

26 May 2016

Sinking sediment in deltas is as important as swelling seas

Sea-level rise due to melting ice is a common worry in coastal areas. But the sea-level story is much more complicated: What lies below the surface — sediment, and the rate at which it compacts — is also an important consideration, especially in deltas.

In a new study, researchers exploring the role of subsurface sediment compaction in coastal subsidence along Egypt’s Nile Delta, most of which lies just a meter above sea level, found subsidence rates there are four times greater than the rate of sea-level rise.

26 Sep 2013

Raising California's Sinking Delta

Over the past century and a half, the river delta that provides Central and Southern Californians with drinking water and farmers with productive cropland has sunk about two and a half centimeters each year. Some of the delta’s islands now lie more than six meters below sea level. Two thousand kilometers of aging levees keep them dry for now, but as the land sinks, the pressure on the levees grows. Researchers at the U.S. Geological Survey in California have uncovered a way to rebuild the delta and sequester carbon in the process.

18 Nov 2008