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Charting the Depths: The World of Subsea Cables



Charting the Depths: The World of Subsea Cables

Charting the Depths: The World of Subsea Cables

Data may be stored in the “cloud,” but when it comes to sending and receiving data, a lot of that action is actually happening along the depths of the ocean floor.

Hidden beneath the waves, these subsea cables account for approximately 95% of international data transmission.

These maps, by Adam Symington, use information from TeleGeography to show the distribution of subsea cables around the planet.

Wired for Connectivity

It’s estimated that there are nearly 1.4 million kilometers (0.9 million miles) of submarine cables in service globally. They ensure emails, content, and calls find their way, linking colossal data centers and facilitating worldwide communication.

Currently, there are 552 active and planned submarine cables:

undersea cables active vs planned

Submarine cables harness fiber-optic technology, transmitting information via rapid light pulses through glass fibers. These fibers, thinner than human hair, are protected by plastic or even steel wire layers.

Cables usually have the diameter of a garden hose, but often with added armor near the shore. Coastal cables are buried under the seabed, hidden from view on the beach, while deep-sea ones rest on the ocean floor.

Length varies widely, from the 131-kilometer CeltixConnect cable, connecting Dublin, Ireland, and Holyhead, UK, to the sprawling 20,000-kilometer Asia America Gateway cable, connecting San Luis Obispo, California, to Hawaii and Southeast Asia:

Asia America Gateway. Image: TeleGeography

With the current technology, cables are designed to last 25 years at least but are often replaced because of damage. Nearly two-thirds of cable damage is caused by fishing vessels and ships dragging anchors.

The Bottom Line

Traditionally dominated by telecom carriers, the makeup of the subsea cable market has shifted over more recent decades. Tech giants like Google, Facebook, Microsoft, and Amazon now heavily invest in new cables.

With data demand surging, at least $10 billion is expected to be invested in subsea cables worldwide between 2022 and 2024, driven by cloud service providers and content streaming platforms.

Even with the growth of satellites in telecom, cables still can carry far more data at a much lower cost than satellites. In fact, according to TeleGeography, satellites account for less than 1% of all U.S. international capacity.

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This article was published as a part of Visual Capitalist's Creator Program, which features data-driven visuals from some of our favorite Creators around the world.

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Ranked: The Top Startup Cities Around the World

Here are the global startup ecosystem rankings, highlighting the scale and maturity of major tech hubs worldwide.



This bar chart shows the top startup ecosystems in the world in 2024.

The Top Startup Cities Around the World

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.

A richly connected network of founders, venture capital firms, and tech talent are some of the key ingredients driving a startup ecosystem.

As engines of growth, these tech clusters are evolving on a global scale. While the world’s leading startup cities are concentrated in America, several ecosystems, such as Beijing and Seoul, are growing in prominence as countries focus on technological advancement to spur innovation.

This graphic shows the best startup cities worldwide, based on data from Pitchbook.

The Global Startup Ecosystem Rankings

To determine the rankings, each city was analyzed based on the scale and maturity of their startup ecosystem over a six-year period ending in the second quarter of 2023.

Among the inputs analyzed and used to calculate the overall development score were fundraising activity, venture capital deals, and exit value:

RankCityDevelopment ScoreCapital RaisedDeal CountExit Value
1🇺🇸 San Francisco90$427.6B19,898$766.3B
2🇺🇸 New York76$179.9B13,594$171.7B
3🇨🇳 Beijing76$161.2B8,835$279.2B
4🇨🇳 Shanghai73$130.3B7,422$186.8B
5🇺🇸 Los Angeles71$144.6B9,781$181.4B
6🇺🇸 Boston70$117.0B6,044$172.8B
7🇬🇧 London64$99.0B11,533$71.9B
8🇨🇳 Shenzhen63$46.4B5,020$66.3B
9🇰🇷 Seoul61$31.1B6,196$71.0B
10🇯🇵 Tokyo60$26.2B5,590$28.0B
11🇨🇳 Hangzhou59$50.7B3,361$88.7B
12🇺🇸 Washington D.C.55$43.7B2,706$28.2B
13🇺🇸 Seattle54$31.7B2,693$35.6B
14🇸🇬 Singapore52$45.7B4,507$38.0B
15🇺🇸 San Diego52$33.5B2,023$44.7B
16🇺🇸 Austin52$26.4B2,636$22.9B
17🇨🇳 Guangzhou52$24.7B1,700$24.0B
18🇮🇱 Tel Aviv51$21.0B1,936$32.2B
19🇺🇸 Denver51$26.8B2,489$29.9B
20🇩🇪 Berlin50$31.2B2,469$15.9B

San Francisco dominates the pack, with $427.6 billion in capital raised over the six-year period.

Despite a challenging funding environment, nearly 20,000 deals closed, highlighting its outsized role in launching tech startups. Both OpenAI and rival Anthropic are headquartered in the city, thanks to its broad pool of tech talent and venture capital firms. Overall, 11,812 startups were based in the San Francisco Bay Area in 2023, equal to about 20% of startups in America.

Falling next in line is New York City, which raised $179.9 billion over the same time period. Crypto firm Gemini and machine learning company, Hugging Face, are two examples of startups based in the city.

As the top-ranking hub outside of America, Beijing is home to TikTok’s parent company, ByteDance, which is one of the most valuable private companies in the world.

In recent years, much of the startup funding in China is being driven by government-backed funds. In particular, these funds are focusing heavily on “hard tech” such as semiconductor-makers and electric vehicle companies that align with the government’s strategic long-term goals.

Another leading tech hub, Singapore, has the highest venture capital funding per capita worldwide. In 2023, this was equal to an impressive $1,060 in venture funding per person. By comparison, venture funding was $345 per person in the U.S., the second-highest globally.

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