What's the difference between an ocean, sea, and saltwater lake?

A simple pictorial explanation of ocean geography

Visualizing ocean geographical features, such as a coastal zone, continental shelf and abyssal plain. This article from the US Geological Survey also provides several links to diverse ocean facts.

Geodesists define sea level using gravity rather than the ocean's height

The sea level is not the same everywhere because the Earth isn't perfectly spherical or has a uniform composition and density. Earth's gravitational field is carefully measured to determine where the sea level would be, even in places with no water.

The Great Salt Lake's distinct dual coloration results from high-salinity organisms that only live in the northern portion and produce a purple protein.

How flooding the Dead Sea could help the climate

There are many dead zones in the world with low elevation and very little rainfall that provide little to no benefits to the ecosystem or climate. This digestible, thorough article explains how piping in nearby water to flood these areas could...

The Great Salt Lake's distinct dual coloration results from high-salinity organisms that only live in the northern portion and produce a purple protein.

The 10 most amazing deep sea creatures

In this video, researchers from the world-renowned Monterey Bay Aquarium discuss the most fascinating deep sea creatures, and how they developed some of their strangest features.

Distinguishing club soda, seltzer, and sparkling water

The three forms of drinking water are similar, but their differences lie mostly in the presence and proportion of minerals and carbonation. Read this quick explainer on the major differences.

Visualizing changes in ocean temperatures between 2016 and 2020

How much does the temperature of the sea change in a given year? This visualization helps illustrate the changes by showing sea surface temperature data from January 2016 through March 2020. Sea surface temperature, which refers to water temperature at the sea's surface, plays a significant role in climate and weather.

Desalination involves costly, energy-intensive methods for producing freshwater

Thermal desalination heats saltwater to produce steam, and reverse osmosis forces saltwater through a membrane that only allows water through. In both cases, freshwater is collected and remineralized for consumption, while wastewater brine is often returned to the ocean, where it may harm marine organisms.

Hot, semiarid, coastal, cold: An overview of the four desert types

This article describes the various characteristics of deserts, including their geography, their climate, their soil, and the wildlife and vegetation that inhabit them. All desert climates are characterized by extreme temperatures and low rainfall,...

How five of the world's most expensive salt and spices are made

Part of the charm of certain spices and salts is their exotic origin, hailing from difficult-to-access locales or hewn via special processes. That also explains why they can be so expensive. Dive into the businesses of producing and marketing five of the world's most expensive food additives with this engaging video.

Explore the animals that populate the depths of the ocean, from fish and coral in the first few hundred feet, all the way down to the bottom of the Mariana Trench.

The difference between solstice and equinox, explained

A solstice marks the extremes in the amount of day or night, while the equinoxes come on days with a balance between the two. Learn why with this brief video.

A fast explainer on every Winter Olympic sport

Slalom, luge, skimo: The 16 sports at the Winter Olympics aren't the most familiar to everyday audiences. They can be divided into three categories: track, indoor, and outdoor. This video breaks down each sport's rules and quirks and the variations of its events in less than eight minutes.

The Great Lakes hold almost 20% of the world's surface freshwater

Formed by retreating glaciers, the Great Lakes system feeds Niagara Falls through the Niagara River. Together, the lakes contain about 23 quadrillion liters (5,400 cubic miles) of water, enough to cover the land portion of the continental US to a depth of 3 meters (9.84 feet).

Moon 101: NASA's complete overview of our lunar companion

From modulating our tides to impact our climate, Earth's lone natural satellite plays a key role forming the planet's habitat. Before diving into the rest of the resources on this page, check out NASA's overview of the basics of the Moon—how it got its name, its size and distance from Earth, its structure, and much more.

The best beach in every US state

Not every state has coastline, but every state has a beach. This list highlights the best sandy shorelines in every US state, whether near the ocean, a lake, or a river.

Wrestling terms you need to know

Wrestling may be scripted, but it’s built on its own vocabulary. From "babyfaces" and "heels" to "kayfabe" and "finishers," this explainer breaks down the key terms that shape what fans see in the ring—and what’s really going on behind the scenes.

Here's how the seven types of plastics fare in the recycling process

To help you make better-informed decisions about the products that you buy, here's a simple explanation of the seven different types of plastic, how they differ, and their impact on the environment.

An investigation suggests a Scottish island became awash in forever chemicals via seafoam and seaspray—raising questions about what that means for the safety of other coastal areas.

The '7 Summits' is a challenge featuring every continent's highest peak

Some devoted mountaineers aim to tackle the seven highest summits in the world: Mount Everest (Asia), Aconcagua (South America), Mount McKinley (North America), Mount Kilimanjaro (Africa), Mount Elbrus (Europe), Mount Vinson (Antarctica), and either Mount Kosciuszko or the Carstensz Pyramid (Oceania).

The seven major US freight rail companies

The US railroad industry is dominated by seven long-running freight conglomerates. Get the basics on each of these companies with this brief overview.

A deeper walk through of the four stages of sleep

In this TED video, sleep expert Matthew Walker carefully breaks down the sleep stages along with a description of why each is important. He finishes the discussion by examining the consequences of altered or decreased sleep, and why seemingly small alterations in our sleep patterns can have outsized effects.

The four types of seismic waves are categorized as body or surface waves

Primary (P) and secondary (S) waves are compression and shear waves, respectively, and travel through Earth’s interior, though secondary waves only move through solids. These waves’ energy is converted into rolling Rayleigh or horizontal Love waves at the surface.

With the exception of Earth, the planets are named after Roman gods and goddesses

Mercury, Venus, Mars, Jupiter, Saturn, Uranus, and Neptune are named after the messenger of the gods, the goddess of love, the god of war, the king of gods, the god of agriculture, the god of the sky, and the god of the sea, respectively. "Earth" comes from Old English and Germanic words meaning "ground."

A comprehensive taxonomy of American tacos

Tacos may be a Mexican food, but they're wildly popular in America and in a number of different styles. This lengthy guide from Serious Eats was compiled after visiting more than 1,000 taco shops. It breaks down the differences between the many variations on the form (including breakfast, barbacoa, and Deli Mex) you'll encounter in different regions of the country. We don't recommend reading on an empty stomach!

What's the difference between a stock and a share?

While the words "stock" and "share" are often used interchangeably in casual conversation, they have different meanings. For instance, "stock" is more general, whereas "share" is more precise.

13 unanswered questions about black holes

Here's a quick rundown on black hole basics, the cosmic enigmas digesting massive swaths of the universe and destabilizing our fundamental ideas of space, time, and matter. Learn how they got their name, what happens in the unfortunate instance you fall into one, and more with this list of 13 questions about black holes.

All rainbows are 'raincircles' caused by water droplets separating white sunlight into a spectrum of colors, but Earth's surface blocks the bottom half of the circle from our line of sight.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

Corals are themselves not coral reefs—the term refers to the tiny marine invertebrates that build the rigid reef.

See how fireworks are made and learn how metals like magnesium and copper are responsible for different colors.

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.

Volcanoes 'die' when their supply of magma runs out, if they are shifted away from their underlying magma reservoir, or if they get clogged by collapsing or their magma cooling back into rock.

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

Browse a detailed visual analysis of over 200,000 similes—comparisons that often use 'like' or 'as'—from popular fiction to see how frequently writers the same idiomatic expressions.

Learn how to read a prospectus, the juicy document that any company must file with the SEC before going public.

The Dracula character, now seen as the vampire archetype, was inspired by a seafood-induced nightmare its creator experienced.

Stanford built a Google Maps for the Roman Empire, revealing how much it cost to travel in the ancient world

The Nasdaq's 'Magnificent 7' companies are responsible for roughly 40% of the Nasdaq 100 index's gains, while the remaining 93 companies account for the other 60%.

This poison ivy knowledge quiz—accompanied by photos of the plant's varied forms—may help you identify this common rash-inducing growth.

Some Pokémon have been named after real and fictional organisms, while some real-world species have been named after Pokémon, such as Chilicola charizard and Binburrum zapdos.

Memecoins are a type of cryptocurrency—a form of digital currency with a wide variety of uses—created around popular 'memes,' or viral internet jokes.

El Niño, Spanish for 'the boy,' was named after Jesus Christ because the phenomenon resembled the weather changes observed around Christmastime.

How the most famous Ebola book, The Hot Zone, which sold 3.5 million copies and was translated into 30 languages, got aspects of the disease so wrong.

A researcher recently discovered an interview from 1967 between groundbreaking journalist Joan Didion and the Grateful Dead, years before the band became an institution.

The word 'jazz' evolved from 'jasm,' 19th-century American slang for 'energy'

The United States is one of only around two dozen countries with a fully federal system of government, in which power is divided between national and state governments.

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

A pickleball's loud 'pop' sound can reach 120 decibels, which is equivalent to a hammer hitting a nail