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Mapped: What Did the World Look Like in the Last Ice Age?

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A map of the Earth 20,000 years ago, at the peak of the last ice age, when colder temperatures transformed the planet 
we know so well.

What Did the World Look Like in the Last Ice Age?

What did the world look like during the last ice age? Was it all endless glaciers and frozen ice? The answer is a partial yes—with some interesting caveats.

The Last Glacial Maximum (LGM), colloquially called the last ice age, was a period in Earth’s history that occurred roughly 26,000 to 19,000 years ago.

This map by cartographer Perrin Remonté offers a snapshot of the Earth from that time, using data of past sea levels and glaciers from research published in 2009, 2014, and 2021, alongside modern-day topographical data.

Let’s dive into the differences between the two Earths below.

The Last Ice Age: Low Seas, Exposed Landmasses

During an ice age, sea levels fall as ocean water that evaporates is stored on land on a large scale (ice sheets, ice caps, glaciers) instead of returning to the ocean.

Earth's Ice Cover20,000 Years AgoToday
Surface8%3%
Land25%11%

At the time of the LGM, the climate was cold and dry with temperatures that were 6 °C (11 °F) lower on average. Water levels in the ocean were more than 400 feet below what they are now, exposing large areas of the continental shelf.

In the map above, these areas are represented as the gray, dry land most noticeable in a few big patches in Southeast Asia and between Russia and Alaska. Here are a few examples of regions of dry land from 20,000 years ago that are now under water:

  • A “lost continent” called Sundaland, a southeastern extension of Asia which forms the island regions of Indonesia today. Some scholars see a connection with this location and the mythical site of Atlantis, though there are many other theories.
  • The Bering land bridge, now a strait, connecting Asia and North America. It is central to the theory explaining how ancient humans crossed between the two continents.
  • Another land bridge connected the island of Great Britain with the rest of continental Europe. The island of Ireland is in turn connected to Great Britain by a giant ice sheet.
  • In Japan, the low water level made the Sea of Japan a lake, and a land bridge connected the region to the Asian mainland. The Yellow Sea—famous as a modern-day fishing location—was completely dry.

The cold temperatures also caused the polar parts of continents to be covered by massive ice sheets, with glaciers forming in mountainous areas.

Flora and Fauna in the Last Ice Age

The dry climate during the last ice age brought about the expansion of deserts and the disappearance of rivers, but some areas saw increased precipitation from falling temperatures.

Most of Canada and Northern Europe was covered with large ice sheets. The U.S. was a mix of ice sheets, alpine deserts, snow forests, semi-arid scrubland and temperate grasslands. Areas that are deserts today—like the Mojave—were filled with lakes. The Great Salt Lake in Utah is a remnant from this time.

Africa had a mix of grasslands in its southern half and deserts in the north—the Sahara Desert existed then as well—and Asia was a mix of tropical deserts in the west, alpine deserts in China, and grasslands in the Indian subcontinent.

Several large animals like the woolly mammoth, the mastodon, the giant beaver, and the saber-toothed tiger roamed the world in extremely harsh conditions, but sadly all are extinct today.

However, not all megafauna from the LGM disappeared forever; many species are still alive, including the Bactrian camel, the tapir, the musk ox, and the white rhinoceros—though the latter is now an endangered species.

Will There Be Another Ice Age?

In a technical sense, we’re still in an “ice age” called the Quaternary Glaciation, which began about 2.6 million years ago. That’s because a permanent ice sheet has existed for the entire time, the Antarctic, which makes geologists call this entire period an ice age.

We are currently in a relatively warmer part of that ice age, described as an interglacial period, which began 11,700 years ago. This geological epoch is known as the Holocene.

Over billions of years, the Earth has experienced numerous glacial and interglacial periods and has had five major ice ages:

Major Ice AgesNameTime Period (Years Ago)
1Huronian Glaciation2.4 billion - 2.1 billion
2Cryogenian Glaciation720 million - 635 million
3Andean-Saharan Glaciation450 million - 420 million
4Late Paleozoic ice age335 million - 260 million
5Quaternary Glaciation2.6 million - present

It is predicted that temperatures will fall again in a few thousand years, leading to expansion of ice sheets. However there are a dizzying array of factors that are still not understood well enough to say comprehensively what causes (or ends) ice ages.

A popular explanation says the degree of the Earth’s axial tilt, its wobble, and its orbital shape, are the main factors heralding the start and end of this phenomenon.

The variations in all three lead to a change in how much prolonged sunlight parts of the world receive, which in turn can cause the creation or melting of ice sheets. But these take thousands of years to coincide and cause a significant change in climate.

Furthermore, current industrial activities have warmed the climate considerably and may in fact delay the next ice age by 50,000-100,000 years.

Still on a history kick? Check out Mapped: The Ancient Seven Wonders of the World that captivated people for thousands of years.
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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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Crime

Mapped: The Safest Cities in the U.S.

How safe is small town America? This map reveals the safest cities in the U.S. in terms of the total crime rate per every 1,000 residents.

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safest cities in the u.s.

Mapped: The Safest Cities in America

The phrase “small town America” often conjures up images of white picket fences, well-trimmed lawns, and big houses. But how safe is modern-day suburbia in America?

Some of the smallest places in the country can actually be among the most dangerous. Take for example Bessemer, Alabama, with a population of around 26,000 and a violent crime rate of 33.1 per every 1,000 residents.

That said, there are many small cities that are true havens for families across the United States. This map showcases the safest cities in the U.S., using FBI data and Census Bureau populations compiled by NeighborhoodScout in 2023.

Note: The source only considered cities with a population of 25,000 or higher. This report is based on total index crimes reported in each city, which includes arson, burglary, larceny-theft, motor vehicle theft, murder, rape, armed robbery, and aggravated assault.

Top 100 Safest Cities in the U.S.

40% of the cities in the ranking are located in Northeastern states, which are typically rated the “safest” based on FBI data.

Here’s a closer look at the full list:

RankCityStateTotal Crime Rate
(per 1,000 residents)
Chance of Being
a Victim
1RidgefieldConnecticut1.91 in 510
2FranklinMassachusetts2.91 in 344
3Lake in the HillsIllinois3.11 in 321
4MarshfieldMassachusetts3.31 in 300
5ArlingtonMassachusetts3.41 in 292
6FulshearTexas3.61 in 276
7ZionsvilleIndiana3.61 in 275
8LexingtonMassachusetts3.71 in 270
9MuskegoWisconsin3.81 in 265
10RexburgIdaho3.91 in 253
11IndependenceKentucky3.91 in 253
12OswegoIllinois4.11 in 238
13MiltonMassachusetts4.21 in 233
14NeedhamMassachusetts4.21 in 233
15White LakeMichigan4.21 in 233
16Avon LakeOhio4.31 in 232
17MadisonMississippi4.51 in 221
18WakefieldMassachusetts4.51 in 218
19WindsorColorado4.51 in 218
20South KingstownRhode Island4.71 in 212
21ColleyvilleTexas4.81 in 206
22West BloomfieldMichigan4.91 in 204
23Johns CreekGeorgia4.91 in 202
24BillericaMassachusetts5.11 in 195
25MasonOhio5.11 in 192
26ReadingMassachusetts5.11 in 192
27North AndoverMassachusetts5.21 in 190
28WellesleyMassachusetts5.21 in 189
29MundeleinIllinois5.31 in 187
30BrandonMississippi5.31 in 186
31CumberlandRhode Island5.41 in 184
32AndoverMassachusetts5.41 in 182
33EdwardsvilleIllinois5.51 in 178
34Little ElmTexas5.61 in 176
35MerrimackNew Hampshire5.71 in 172
36WalthamMassachusetts5.81 in 169
37WylieTexas5.91 in 169
38Commerce TownshipMichigan5.91 in 169
39MiltonGeorgia5.91 in 167
40MelroseMassachusetts6.01 in 164
41BallwinMissouri6.11 in 162
42North KingstownRhode Island6.11 in 162
43BeverlyMassachusetts6.21 in 161
44Rochester HillsMichigan6.21 in 160
45KellerTexas6.31 in 158
46ShrewsburyMassachusetts6.41 in 156
47DracutMassachusetts6.41 in 155
48ProsperTexas6.41 in 155
49NewtonMassachusetts6.51 in 152
50FriendswoodTexas6.51 in 152
51McHenryIllinois6.51 in 152
52Fort MillSouth Carolina6.61 in 151
53WallingfordConnecticut6.81 in 146
54CaledoniaWisconsin6.91 in 144
55BelmontMassachusetts6.91 in 144
56De PereWisconsin6.91 in 143
57Flower MoundTexas7.01 in 142
58EastonMassachusetts7.01 in 141
59Highland ParkIllinois7.01 in 141
60CarmelIndiana7.21 in 138
61SachseTexas7.21 in 138
62AlgonquinIllinois7.21 in 137
63HendersonvilleTennessee7.21 in 137
64San LuisArizona7.31 in 136
65FishersIndiana7.31 in 135
66PerrysburgOhio7.41 in 135
67Lake StevensWashington7.41 in 134
68CheshireConnecticut7.41 in 134
69MilfordMassachusetts7.51 in 132
70Saratoga SpringsUtah7.51 in 132
71Bella VistaArkansas7.51 in 132
72PrincetonNew Jersey7.51 in 131
73BlufftonSouth Carolina7.61 in 130
74NoviMichigan7.61 in 130
75ChelmsfordMassachusetts7.61 in 130
76AmherstMassachusetts7.71 in 129
77RosemountMinnesota7.71 in 129
78GloucesterMassachusetts7.71 in 129
79SyracuseUtah7.81 in 127
80WaukeeIowa7.81 in 126
81MequonWisconsin7.91 in 126
82WestfieldIndiana7.91 in 126
83Spring HillTennessee7.91 in 126
84Upper ArlingtonOhio7.91 in 126
85RahwayNew Jersey7.91 in 125
86MontclairNew Jersey7.91 in 125
87GreenwichConnecticut8.01 in 125
88HuttoTexas8.01 in 124
89Vestavia HillsAlabama8.01 in 123
90BrownsburgIndiana8.11 in 123
91WilmetteIllinois8.11 in 123
92New MilfordConnecticut8.11 in 122
93HilliardOhio8.21 in 120
94Royal OakMichigan8.21 in 120
95DerryNew Hampshire8.31 in 121
96DublinOhio8.31 in 120
97West WarwickRhode Island8.51 in 116
98WatertownMassachusetts8.51 in 116
99WalpoleMassachusetts8.61 in 115
100KaysvilleUtah8.61 in 115

One quarter of the safest cities are located in Massachusetts, with the vast majority clustered around Boston.

The median population of the cities and towns in the top 100 is just 32,000, and few widely-recognized cities make the list. Carmel, Indiana (#60) is the only city with a population above 100,000 to make the rankings. This would seem to follow the logic that bigger cities are more dangerous, but our map covering the most dangerous cities in America shows that many small cities were just as dangerous, and some even more.

Regardless, small towns can truly be idyllic. For example, a person’s chance of falling victim to crime in Ridgefield, Connecticut, the safest ranked city in the U.S., is just 1-in-510. That’s an overall rate of fewer than two incidents of crime per every 1,000 residents.

One surprising observation from the data is that many of the safest U.S. cities are in very close proximity to some of the most dangerous.

safest cities in the US location

One example that illustrates this is Detroit, which ranks as the sixth most dangerous city in America. Despite this, as shown on the map above, there are four communities nearby that have some of the lowest crime rates in America.

In other words, America’s metro areas contain much contrast, and these insights provide valuable information for individuals and families seeking secure places to live across the country.

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