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1 Billion Years of Tectonic Plate Movement in 40 Seconds

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1 Billion Years of Tectonic Plate Movement in 40 Seconds

According to plate tectonic theory, the Earth’s surface is made up of slabs of rock that are slowly shifting right under our feet.

Because of this constant movement, today’s Earth looks a lot different from what it did millions of years ago. Today’s animation looks at the Earth’s tectonic plate movement from 1 ga (geological time for 1 billion years ago) to the present-day, via EarthByte on YouTube.

Editor’s note: The video starts at time 1,000 ma (1,000 million years ago), and ticks down at the rate of about 25 million years every second.

The Emergence of Plate Tectonic Theory

Plate tectonics is a relatively new theory—in fact, according to National Geographic, it hadn’t become popular until the 1960s. However, the concept of continental movement was brewing long before it became widely accepted.

In 1912, German scientist Alfred Wegener proposed a theory he called continental drift. According to Wegener’s theory, Earth’s continents once formed a single, giant landmass, which he called Pangaea.

Over millions of years, Pangaea slowly broke apart, eventually forming the continents as they are today. Wegener believed this continental drift explained why the borders of South America and Africa looked like matching puzzle pieces. He also pointed to similar rock formations and fossils on these two continents as proof to back his theory.

Initially, the scientific community wasn’t on board with the theory of continental drift. But as more data emerged over the years, including research on seafloor spreading, the theory started to gain traction.

The Supercontinent Cycle

Nowadays, it’s believed that Pangea was just one of several supercontinents to mass together (and break apart) over the course of geological history.

The exact number of supercontinents is largely debated, but according to the Encylopedia of Geology, here are five (including Pangea) that are widely recognized:

  • Kenorland: 2.7-2.5 billion years ago
  • Nuna/Columbia: 1.6-1.4 billion years ago
  • Rodinia: 950–800 million years ago
  • Pannotia: 620-580 million years ago
  • Pangea: 325-175 million years ago

According to the theory, this cycle of breaking apart and coming together happens because of subduction, which occurs when tectonic plates converge with one another.

The supercontinent cycle also ties into ocean formation. The below example of the Wilson Cycle specifically keys in on how the Atlantic Ocean, and its predecessor, the Iapetus Ocean, were formed as supercontinents drifted apart:

the Wilson Cycle

Source: Hannes Grobe

The Importance of Plate Tectonics

Plate tectonics has been a game-changer for geologists. The theory has helped to explain tons of unanswered geological questions, assisting scientists in understanding how volcanoes, mountains, and ocean ridges are formed.

It’s also valuable for the oil and gas industry since it explains how sedimentary basins were created, allowing geologists and engineers to target and locate vast oil reserves.

Since the theory of plate tectonics is relatively new, there’s still a lot to be discovered in this field of research. However, in March 2021, a report was published in Earth-Science Reviews that, for the first time, visualized a continuous plate model that shows how Earth’s plates have shifted over the last billion years.

The video above visualizes this particular report and accurately depicts the Earth’s tectonic plates’ movement or the observed shift in Earth’s tectonic plates over the years.

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United States

Mapped: U.S. States By Number of Cities Over 250,000 Residents

Eighteen U.S. States don’t have a single incorporated area with more than 250,000 people.

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A cropped map showing the number of cities with 250,000+ residents in each U.S. state.

Mapped: U.S. States By Number of Cities Over 250K Residents

This was originally posted on our Voronoi app. Download the app for free on iOS or Android and discover incredible data-driven charts from a variety of trusted sources.

Over 80% of the American population lives in an “urban area” according to the U.S. Census Bureau. But where are all of the country’s largest cities, and what patterns can we see from their state locations?

This map shows U.S. states by their number of incorporated areas (i.e. cities or towns) that have more than 250,000 residents. Data for this map comes from 2024 estimates made by World Population Review, which were based on the latest U.S. Census Bureau figures.

ℹ️ An incorporated area is a legally recognized region with its own local government, empowered to enact and enforce laws within its boundaries, often including cities, towns, or villages.

Ranked: U.S. States By Number of Cities Over 250K Residents

California and Texas—also the most populous U.S. states—each have more than 10 cities with at least a quarter of a million inhabitants.

StateCities With 250K
People
City Names
California15Los Angeles, San
Diego, San Jose,
San Francisco,
Fresno, Sacramento,
Long Beach, Oakland,
Bakersfield, Anaheim,
Riverside, Stockton,
Irvine, Santa Ana,
Chula Visa
Texas12Houston, San
Antonio, Dallas,
Fort Worth, Austin,
El Paso, Arlington,
Corpus Christi, Plano,
Lubbock, Laredo,
Irving
Arizona6Phoenix, Tucson,
Mesa, Chandler,
Gilbert, Glendale
Florida6Jacksonville, Miami,
Tampa, Orlando,
St. Petersburg,
Port St. Lucie
North Carolina5Charlotte, Raleigh,
Greensboro, Durham,
Winston-Salem
Ohio4Columbus, Cleveland,
Cincinnati, Toledo
Nevada4Las Vegas, Henderson,
North Las Vegas,
Reno
Colorado3Denver, Colorado
Springs, Aurora
Tennessee2Nashville, Memphis
New York2New York, Buffalo
Pennsylvania2Philadelphia, Pittsburgh
Indiana2Indianapolis,
Fort Wayne
Oklahoma2Oklahoma City, Tulsa
Kentucky2Louisville/Jefferson
County, Lexington
Wisconsin2Milwaukee, Madison
Missouri2Kansas City, St. Louis
Nebraska2Omaha, Lincoln
Virginia2Virginia Beach,
Chesapeake
Minnesota2Minneapolis, St. Paul
New Jersey2Newark, Jersey City
Illinois1Chicago
Washington1Seattle
District of Columbia1Washington D.C.
Massachusetts1Boston
Oregon1Portland
Michigan1Detroit
New Mexico1Albuquerque
Maryland1Baltimore
Georgia1Atlanta
Kansas1Wichita
Louisiana1New Orleans
Hawaii1Honolulu
Alaska1Anchorage

Two other warm weather states, Arizona and Florida, also have a number of cities with 250,000 or more residents, at six each.

Eighteen U.S. states in total—including South Carolina, Alabama, and Utah to name a few—have no single incorporated area with 250,000 or more residents.

Cities, Towns, and Metro Areas

Like with all population data, definitions tend to play a big role in what is considered a city. In general parlance, built-up population centers are often thought of cities. However, an urban area can have a relatively big population and be incorporated as a town, as in the case of Gilbert, Arizona, which is included in the above map.

Separately, a collection of incorporated villages can be collectively referred to as a town, such as in the case of Hempstead, New York. Hempstead is an incorporated village with only 60,000 people, however it also lends its name to the wider town (an amalgamation of 22 villages and 38 hamlets) which has nearly 800,000 inhabitants. Three other New York towns listed below thus do not make the map for similar reasons.

TownStatePopulation
HempsteadNew York779,916
BrookhavenNew York483,351
IslipNew York333,322
Oyster BayNew York293,812

Source: World Population Review.

On the other hand, major hubs like Los Angeles often have a central city and surrounding suburbs, which are their own distinct incorporated cities as well. These are often counted as one major metropolitan region, but are still, technically separate cities. This leads to interesting results in the final count.

For example, in Arizona’s case, five of the six cities listed all belong to the greater Phoenix Metropolitan region.

Meanwhile, Nevada has two main population centers: Las Vegas and Reno. However two of Las Vegas’ suburbs, Henderson and North Las Vegas, are separately incorporated, and each have populations that crack the 250,000 mark.

Conversely, in South Carolina, there are no cities listed, despite having a state population of 5.3 million. The state’s urban areas are divided up in such a way that none of them (including the central cities of Charleston, Columbia, and Greenville) end up passing 250,000 in population.

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