1. What is the hottest place on
Count one wrong if you guessed Death Valley in California.
True enough on many days. But El Azizia in Libya recorded a
temperature of 136 degrees Fahrenheit (57.8 Celsius) on
Sept. 13, 1922 — the hottest ever measured. In Death Valley,
it got up to 134 Fahrenheit on July 10, 1913.
2. And the coldest place around here?
Far and away, the coldest temperature
ever measured on Earth was -129 Fahrenheit (-89 Celsius) at
Vostok, Antarctica, on July 21, 1983.
3. What makes thunder?
If you thought, “Lightning!” then
hats off to you. But I had a more illuminating answer in
mind. The air around a lightning bolt is superheated to
about five times the temperature of the sun. This sudden
heating causes the air to expand faster than the speed of
sound, which compresses the air and forms a shock wave; we
hear it as thunder.
4. Can rocks
a volcanic eruption, the violent separation of gas from lava
produces a “frothy” rock called pumice, loaded with gas
bubbles. Some of it can float, geologists say. I’ve never
seen this happen, and I’m thankful for that.
5. Can rocks
but observing the process is less interesting than watching
paint dry. Rocks called iron-manganese crusts grow on
mountains under the sea. The crusts precipitate material
slowly from seawater, growing about 1 millimeter every
million years. Your fingernails grow about the same amount
every two weeks.
6. How much
space dust falls to Earth each year?
Estimates vary, but the USGS says at
least 1,000 million grams, or roughly 1,000 tons of material
enters the atmosphere every year and makes its way to
Earth’s surface. One group of scientists claims microbes
rain down from space, too, and that extraterrestrial
organisms are responsible for flu epidemics. There’s been no
proof of this, and I’m not holding my breath.
7. How far does
regular dust blow in the wind?
A 1999 study showed that African dust
finds its way to Florida and can help push parts of the
state over the prescribed air quality limit for particulate
matter set by the U.S. Environmental Protection Agency. The
dust is kicked up by high winds in North Africa and carried
as high as 20,000 feet (6,100 meters), where it’s caught up
in the trade winds and carried across the sea. Dust from
China makes its way to North America, too.
8. Where is the
world’s highest waterfall?
The water of Angel Falls in Venezuela
drops 3,212 feet (979 meters).
9. What two
great American cities are destined to merge?
The San Andreas fault, which runs
north-south, is slipping at a rate of about 2 inches (5
centimeters) per year, causing Los Angeles to move towards
San Francisco. Scientists forecast L.A. will be a suburb of
the City by the Bay in about 15 million years.
10. Is Earth a sphere?
Because the planet rotates and is
more flexible than you might imagine, it bulges at the
midsection, creating a sort of pumpkin shape. The bulge was
lessening for centuries but now, suddenly, it is growing, a
recent study showed. Accelerated melting of Earth’s glaciers
is taking the blame for the gain in equatorial girth.
11. What would a
100-pound person weigh on Mars?
The gravity on Mars is 38 percent of
that found on Earth at sea level. So a 100-pound person on
Earth would weigh 38 pounds on Mars. Based on NASA’s present
plans, it’ll be decades before this assumption can be
observationally proved, however.
12. How long is
a Martian year?
It’s a year long, if you’re from
Mars. To an earthling, it’s nearly twice as long. The Red
Planet takes 687 Earth days to go around the sun — compared
with 365 days for Earth. Taking into account Mars’ different
rotational time (see No. 13 below) calendars on Mars would
be about 670 days long with some leap days needed to keep
things square. If you find one, please mail it to me. I’m
curious how they worked out the months, given they have two
moons. (The initial publication of this fact mistakenly said
a Mars calendar would have 687 days.)
13. How long is
the average Martian day?
A Martian can sleep (or work) an
extra half-hour every day compared to you. Mars days are 24
hours and 37 minutes long, compared with 23 hours, 56
minutes on Earth. A day on any planet in our solar system is
determined by how long it takes the world to spin once on
its axis, making the sun appear to rise in the morning and
sending it down in the evening.
14. What is the
The Mauna Loa volcano in Hawaii holds
the title here on Earth. It rises more than 50,000 feet (9.5
miles or 15.2 kilometers) above its base, which sits under
the surface of the sea. But that’s all volcanic chump
change. Olympus Mons on Mars rises 16 miles (26 kilometers)
into the Martian sky. Its base would almost cover the entire
state of Arizona.
15. What was the
deadliest known earthquake?
The world’s deadliest recorded
earthquake occurred in 1557 in central China. It struck a
region where most people lived in caves carved from soft
rock. The dwellings collapsed, killing an estimated 830,000
people. In 1976 another deadly temblor struck Tangshan,
China. More than 250,000 people were killed.
16. What was the
strongest earthquake in recent times?
A 1960 Chilean earthquake, which
occurred off the coast, had a magnitude of 9.6 and broke a
fault more than 1,000 miles (1,600 kilometers) long. An
earthquake like that under a major city would challenge the
best construction techniques.
earthquake was more catastrophic: Kobe, Japan or Northridge,
The 1994 Northridge earthquake had a
magnitude of 6.7 and was responsible for approximately 60
deaths, 9,000 injuries and more than $40 billion in damage.
The Kobe earthquake of 1995 was magnitude 6.8 and killed
5,530 people. There were 37,000 injuries and more than $100
billion in economic loss.
18. How far is
it to the center of the earth?
The distance from the surface of
Earth to the center is about 3,963 miles (6,378 kilometers).
Much of Earth is fluid. The mostly solid skin of the planet
is only 41 miles (66 kilometers) thick — thinner than the
skin of an apple, relatively speaking.
19. What is the
Climbers who brave Mount Everest in
the Nepal-Tibet section of the Himalayas reach 29,035 feet
(nearly 9 kilometers) above sea level. Its height was
revised upward by 7 feet based on measurements made in 1999
using the satellite-based Global Positioning System.
20. Has the moon
always been so close?
It used to be much closer! A billion
years ago, the moon was in a tighter orbit, taking just 20
days to go around us and make a month. A day on Earth back
then was only 18 hours long. The moon is still moving away —
about 1.6 inches (4 centimeters) a year. Meanwhile, Earth’s
rotation is slowing down, lengthening our days. In the
distant future, a day will be 960 hours long! (Find out
21. Where is the lowest dry point on
The shore of the Dead Sea in the Middle East is about 1,300
feet (400 meters) below sea level. Not even a close second
is Bad Water in Death Valley, Calif., at a mere 282 feet
below sea level.
22. Good thing
California isn’t sinking further, right?
Actually parts of it are, which is so
interesting that I snuck this non-question onto the list. In
a problem repeated elsewhere in the country, the pumping of
natural underground water reservoirs in California is
causing the ground to sink up to 4 inches (11 centimeters)
per year in places. Water and sewage systems may soon be
23. What is the
The Nile River in Africa is 4,160
miles (6,695 kilometers) long.
24. What is the
most earthquake-prone state in the United States?
Alaska experiences a magnitude 7
earthquake almost every year, and a magnitude 8 or greater
earthquake on average every 14 years. Florida and North
Dakota get the fewest earthquakes in the states, even fewer
than New York.
25. What’s the
driest place on Earth?
A place called Arica, in Chile, gets
just 0.03 inches (0.76 millimeters) of rain per year. At
that rate, it would take a century to fill a coffee cup.
26. What causes
Intense rainfall over a short period
of time can trigger shallow, fast-moving mud and debris
flows. Slow, steady rainfall over a long period of time may
trigger deeper, slow-moving landslides. Different materials
behave differently, too. Every year as much as $2 billion in
landslide damage occurs in the United States. In a
record-breaking storm in the San Francisco area in January
1982, some 18,000 debris flows were triggered during a
single night! Property damage was over $66 million, and 25
27. How fast can
Debris flows are like mud avalanches that can move at speeds
in excess of 100 mph (160 kilometers per hour).
28. Do things
inside Earth flow?
You bet. In fact, scientists found in
1999 that molten material in and around Earth’s core moves
in vortices, swirling pockets whose dynamics are similar to
tornadoes and hurricanes. And as you’ll learn later in this
list, the planet’s core moves in other strange ways, too.
29. What is the
wettest place on Earth?
Lloro, Colombia, averages 523.6
inches of rainfall a year, or more than 40 feet (13 meters).
That’s about 10 times more than fairly wet major cities in
Europe or the United States.
30. Does Earth
go through phases, like the moon?
From Mars, Earth would be seen to go
through distinct phases (just as we see Venus change
phases). Earth is inside the orbit of Mars, and as the two
planets travel around the sun, sunlight would strike our
home planet from different angles during the year. Earth
phases can be seen in recent photographs taken by Mars
Global Surveyor and the European Mars Express.
31. What is the
The Grand Canyon is billed as the
world’s largest canyon system. Its main branch is 277 miles
(446 kilometers) long. But let’s compare. Valles Marineris
on Mars extends for about 3,000 miles (4,800 kilometers). If
it were added to a U.S. map, it would stretch from New York
City to Los Angeles. In places this vast scar on the Martian
surface is 5 miles (8 kilometers) deep.
32. What is the
deepest canyon in the United States?
Over the eons, the Snake River dug
Hell’s Canyon along the Oregon-Idaho border. It is more than
8,000 feet (2.4 kilometers) deep. In contrast, the Grand
Canyon is less than 6,000 feet deep — a bit more than a
33. Is Earth the largest rocky planet
in the solar system?
Just barely! Earth’s diameter at the
equator is 7,926 miles (12,756 kilometers). Venus is 7,521
miles (12,104 kilometers) wide. Mercury and Mars, the other
two inner rocky planets, are much smaller. Pluto is rocky,
too, but it’s comparatively tiny (and some say it is not a
planet at all).
34. How many of
Earth’s volcanoes are known to have erupted in historic
About 540 volcanoes on land are known. No one knows how many
undersea volcanoes have erupted through history.
35. Is air mostly oxygen?
Earth’s atmosphere is actually about
80 percent nitrogen. Most of the rest is oxygen, with tiny
amounts of other stuff thrown in.
36. What is the
highest waterfall in the United States?
Yosemite Falls in California is 2,425
feet (739 meters).
percentage of the world’s water is in the oceans?
About 97 percent. Oceans make up
about two-thirds of Earth’s surface, which means that when
the next asteroid hits the planet, odds are good it will
38. Which two
land masses contain the vast majority of the Earth’s fresh
Nearly 70 percent of the Earth’s
fresh-water supply is locked up in the icecaps of Antarctica
and Greenland. The remaining fresh-water supply exists in
the atmosphere, streams, lakes, or groundwater and accounts
for a mere 1 percent of Earth’s total.
39. Which of
Earth’s oceans is the largest?
The Pacific Ocean covers 64 million
square miles (165 million square kilometers). It is more
than two times the size of the Atlantic. It has an average
depth of 2.4 miles (3.9 kilometers).
40. Why is Earth mostly crater-free
compared to the pockmarked moon?
Earth is more active, in terms of
both geology and weather. Much of our planet’s geologic
history was long ago folded back inside. Some of that is
regurgitated by volcanoes, but the results are pretty hard
to study. Even more recent events evident on the surface —
craters that can by millions of years old — get overgrown by
vegetation, weathered by wind and rain, and modified by
earthquakes and landslides. The moon, meanwhile, is
geologically quiet and has almost no weather; its craters
tell a billions-year-long tale of catastrophic collisions.
Interestingly, some of the oldest Earth rocks might be
awaiting discovery on the moon, having been blasted there
billions of years ago by the very asteroid impacts that
rattle both worlds.
41. How much
surface area does Earth contain?
There are 196,950,711 square miles
(510,100,000 square kilometers).
42. What is the
largest lake in the world?
By size and volume it is the Caspian
Sea, located between southeast Europe and west Asia.
43. Where do
most earthquakes and volcanic eruptions occur on Earth?
The majority occur along boundaries
of the dozen or so major plates that more or less float on
the surface of Earth. One of the most active plate
boundaries where earthquakes and eruptions are frequent, for
example, is around the massive Pacific Plate commonly
referred to as the Pacific Ring of Fire. It fuels shaking
and baking from Japan to Alaska to South America.
44. How hot are
the planet’s innards?
The temperature of Earth increases
about 36 degrees Fahrenheit (20 degrees Celsius) for every
kilometer (about 0.62 miles) you go down. Near the center,
its thought to be at least 7,000 degrees Fahrenheit (3,870
45. What three countries have the
greatest number of historically active volcanoes?
The top three countries are
Indonesia, Japan and the United States in descending order
46. How many
people worldwide are at risk from volcanoes?
As of the year 2000, USGS scientists
estimated that volcanoes posed a tangible risk to at least
500 million people. This is comparable to the entire
population of the world at the beginning of the seventeenth
47. Which of the following sources
stores the greatest volume of fresh water worldwide: lakes,
streams or ground water?
Groundwater comprises a 30 times
greater volume than all freshwater lakes, and more than
3,000 times what’s in the world’s streams and rivers at any
given time. Groundwater is housed in natural underground
aquifers, in which the water typically runs around and
through the stone and other material.
earthquake was larger, the 1906 San Francisco earthquake or
the 1964 Anchorage, Alaska, temblor?
The Anchorage earthquake had a
magnitude of 9.2, whereas the San Francisco earthquake was a
magnitude 7.8. This difference in magnitude equates to 125
times more energy being released in the 1964 quake and
accounts for why the Anchorage earthquake was felt over an
area of almost 500,000 square miles (1,295,000 square
earthquake was more destructive in terms of loss of life and
relative damage costs, the 1906 San Francisco earthquake or
the 1964 Anchorage earthquake?
The 1906 San Francisco earthquake
tops this category. It was responsible for 700 deaths vs.
114 from the Anchorage earthquake. Property damage in San
Francisco was also greater in relative terms due to the
destructive fires that destroyed mostly wooden structures of
50. Is Earth’s core solid?
The inner portion of the core is
thought to be solid. But the outer portion of the core
appears molten. We’ve never been there though, so scientists
aren’t sure of the exact composition. A radical
Hollywoodlike idea was recently put forth to blow a crack in
the planet and send a probe down there to learn more. An
interesting bit of recent evidence shows Mars’ core may be
similarly squishy. Scientists figured this out by studying
tides on Mars (tides on Mars?).
51. Does all of
Earth spin at the same rate?
The solid inner core — a mass of iron
comparable to the size of the moon — spins faster than the
outer portion of the iron core, which is liquid. A study in
1996 showed that over the previous century, the extra speed
caused the inner core to gain a quarter-turn on the planet
as a whole. So the inner core makes a complete revolution
with respect to the rest of Earth in about 400 years.
Immense pressure keeps it solid.
52. How many
people have been killed by volcanoes during the last 500
least 300,000. Between 1980 and 1990, volcanic activity
killed at least 26,000 people.
53. How much of
Earth’s surface consists of volcanic rock?
Scientists estimate that more than
three-quarters of Earth’s surface is of volcanic origin —
that is, rocks either erupted by volcanoes or molten rock
that cooled below ground and has subsequently been exposed
at the surface. Most of Earth’s volcanic rocks are found on
the sea floor.
54. Can an
earthquake cause a tsunami?
If the earthquake originates under
the ocean, yes. Near the earthquake’s epicenter, the sea
floor rises and falls, pushing all the water above it up and
down. This motion produces a wave that travels outward in
all directions. A tsunami can be massive but remain
relatively low in height in deep water. Upon nearing the
shore, it is forced up and can reach the height of tall
buildings. One in 1964 was triggered in Alaska and swamped
the small Northern California town of Crescent City, moving
train cars several blocks and killing several people there.
Asteroids can cause tsunami, too.
55. Are all tsunamis high waves when
they strike a coastline?
No, contrary to many artistic images
of tsunamis, most do not result in giant breaking waves.
Rather, most tsunamis come onshore more like very strong and
fast tides. The water can rise higher than anyone along a
given shore area has ever seen, however.
56. How much of
Earth’s land surface is desert?
57. What’s the
deepest place in the ocean?
The greatest known depth is 36,198
feet (6.9 miles or 11 kilometers) at the Mariana Trench, in
the Pacific Ocean well south of Japan near the Mariana
58. What is the fastest surface wind
The fastest “regular” wind that’s
widely agreed upon was 231 mph (372 kilometers per hour),
recorded at Mount Washington, N.H., on April 12, 1934. But
during a May 1999 tornado in Oklahoma, researchers clocked
the wind at 318 mph (513 kilometers per hour). For
comparison, Neptune’s winds can rage to 900 mph (1,448
kilometers per hour).
59. How much
fresh water is stored in the earth?
More than 2 million cubic miles of
fresh water is stored in the planet, nearly half of it
within a half-mile of the surface. Mars, too, appears to
have a lot of water near its surface, but what’s been
detected so far is locked up as ice; nobody has estimated
how much might be there.
60. How old is
Our planet is more than 4.5 billion years old, just a shade
younger than the sun. Recent evidence actually shows that
Earth was formed much earlier than previously believed, just
10 million years after the birth of the sun, a stellar event
typically put at 4.6 billion years ago.
61. What is the
world’s largest desert?
The Sahara Desert in northern Africa
is more than 23 times the size of southern California’s
62. Which planet
has more moons, Earth or Mars?
Mars has two satellites, Phobos and
Deimos. Earth has only one natural satellite, but it’s the
moon. The outer planets have lots of moons, most of them
found fairly recently and leading to the possibility that
scientists might one day need to redefine what it means to
be a moon.
63. What is the world’s deepest lake?
Lake Baikal in the south central part
of Siberia is 5,712 feet (1.7 kilometers) deep. It’s about
20 million years old and contains 20 percent of Earth’s
fresh liquid water.
64. What is the
origin of the word “volcano”?
It derives from Vulcan, the Roman god
65. How many minerals are known to
There are roughly 4,000 known minerals, although only about
200 are of major importance. Approximately 50-100 new
minerals are described each year.
66. What is the
total water supply of the world?
The total water supply of the world
is 326 million cubic miles (1 cubic mile of water equals
more than 1 trillion gallons).
67. What is the
world’s largest island?
Greenland covers 840,000 square miles
(2,176,000 square kilometers). Continents are typically
defined as land masses made of low-density rock that
essentially floats on the molten material below. Greenland
fits this description, but it’s only about one-third the
size of Australia. Some scientists call Greenland an island,
others say it’s a continent.
68. Where are
most of Earth’s volcanoes?
The most prominent topographic
feature on Earth is the immense volcanic mountain chain that
encircles the planet beneath the sea — the chain is more
than 30,000 miles (48,000 kilometers) long and rises an
average of 18,000 feet (5.5 kilometers) above the seafloor.
It is called the mid-ocean ridge and is where Earth’s plates
spread apart as new crust bubbles up — volcanic activity.
There are more volcanoes here than on land. The spreading,
however, leads to scrunching when these plates slam into the
continents. The result: more volcanoes and earthquakes in
places like California and Japan.
69. What volcano
killed the most people?
The eruption of Tambora volcano in
Indonesia in 1815 is estimated to have killed 90,000 people.
Most died from starvation after the eruption, though,
because of widespread crop destruction, and from water
contamination and disease.
70. Were Earth
and the moon separated at birth?
Not quite. But leading theory holds
that our favorite satellite was carved partly from Earth
shortly after the Earth formed. A Mars-sized object slammed
into our fledgling planet. The impactor was destroyed. Stuff
flew everywhere and a lot of it went into orbit around
Earth. The moon gathered itself together out of the largely
vaporized remains of the collision, while Earth hung in
there pretty much intact.
71. How many
lightning strikes occur worldwide every second?
On average, about 100. Those are just
the ones that hit the ground, though. During any given
minute, there are more than a thousand thunderstorms around
Earth causing some 6,000 flashes of lightning. A lot of it
goes from cloud to cloud.
72. Are rivers
in the traditional sense, of course. But like all living
creatures, rivers have a life span. They are born, grow in
size, and they age. They can even die during the span of
asteroids create islands?
Speculation has existed for decades
that ancient asteroid impacts might create hot spots of
volcanic activity, which could give rise to mountains that
poke up through seas that didn’t used to be there. There’s
no firm answer to this question, but a recent computer model
suggested Hawaii might have been formed in this manner.
74. Is the state of Louisiana growing
Louisiana loses about 30 square miles
(78 square kilometers) of land each year to coastal erosion,
hurricanes, other natural and human causes and a thing
called subsidence, which means sinking. Much of New Orleans
actually sits 11 feet (3.4 meters) below sea level. Parts of
the French quarter have sunk 2 feet in the past six decades.
The city is protected by dikes, but all experts agree that
storm tides from a direct hit by a major hurricane would
breach the system and swamp much of the city. In 2000, the
director of the U.S. Geological Survey, Chip Groat, said:
“With the projected rate of subsidence, wetland loss and
sea-level rise, New Orleans will likely be on the verge of
extinction by this time next century.”
75. How much
would seas rise if the Antarctic Ice Sheet melted?
The Antarctic Ice Sheet holds nearly
90 percent of the world’s ice and 70 percent of its fresh
water. If the entire ice sheet were to melt, sea level would
rise by nearly 220 feet, or the height of a 20-story
building. Scientists know there’s a melting trend under way.
The United Nations has said that in a worst-case scenario —
depending on how much global air temperatures increase —
seas could jump 3 feet (1 meter) by 2100.
76. Is ice a
Yes, ice is a mineral and is formally described as such in
Dana’s System of Mineralogy.
77. What is the
softest of all minerals?
Talc is the softest of minerals. It
is commonly used to make talcum powder.
78. What is the
hardest of all minerals?
The one that becomes emotionally
useless after a divorce but still retains monetary value.
79. How are
colors produced in fireworks?
Mineral elements taken from Earth
provide the colors. Strontium yields deep reds, copper
produces blue, sodium yields yellow, and iron filings and
charcoal pieces produce gold sparks. Bright flashes and loud
bangs come from aluminum powder.
80. Does Earth
have the worst weather in the solar system?
Right now, it’s the worst that most
humans I know ever experience. But there’s lots of wilder
weather elsewhere. Mars can whip up hurricanelike storms
four times bigger than Texas. Dust storms on the Red Planet
can obscure the entire globe! Jupiter has a hurricane twice
the size our entire planet, and it’s lasted for at least
three centuries (another storm on Jupiter is even bigger).
Venus is a living hell, and Pluto is routinely more frigid
than the coldest place on Earth (though may change one day,
and Pluto may in fact become the last oasis for life).
81. Where are the highest tides?
In Burntcoat Head, Minas Basin, part
of the Bay of Fundy in Nova Scotia, tides can range 38.4
feet (11.7 meters). The bay is funnel-shaped — its bottom
slopes upward continuously from the ocean inlet. The result
is an extreme “tidal bore,” a wavelike phenomenon at the
leading edge of the changing tide. Bores in Fundy can travel
up feeder rivers at 8 mph (13 kilometers per hour) and be
more than 3 feet (1 meter) tall.
82. Where is the
world’s only equatorial glacier?
Mount Cotopaxi in Ecuador supports
the only glacier on the equator.
83. What is the
largest lake in North America?
84. What’s the
deadliest hurricane to ever hit the United States?
A Category 4 hurricane hit Galveston,
Texas in 1900 and killed more than 6,000 people. The next
closest death toll was less than 1,900 from a 1928 Florida
85. What is the longest mountain
chain on Earth?
The Mid-Atlantic Ridge, which splits
nearly the entire Atlantic Ocean north to south. Iceland is
one place where this submarine mountain chain rises above
the sea surface.
86. How much
gold has been discovered worldwide to date?
More than 193,000 metric tons (425
million pounds). If you stuck it all together, it would make
a cube-shaped, seven-story structure that might resemble one
of Donald Trump’s buildings. First you’d have to find all
those rings that have gone down the drain.
87. What are the
two major gold-producing countries?
South Africa produces 5,300 metric
tons per year, and the United States produces more than
3,200 metric tons.
88. What North
American plant can live for thousands of years?
The creosote bush, which grows in the
Mojave, Sonoran, and Chihuahuan deserts, has been shown by
radiocarbon dating to have lived since the birth of Christ.
Some of these plants may endure 10,000 years, scientists
say. If only they could talk.
89. On average,
how much water is used worldwide each day?
About 400 billion gallons.
90. Is Saturn
the only ringed planet?
Saturn has the most obvious rings.
But Jupiter and Neptune both have subtle ring systems. And
even Earth may once have been a ringed planet, the result of
some space rock’s glancing blow.
91. What is the
highest, driest, and coldest continent on Earth?
That would be Antarctica.
92. At what
depth do most earthquakes occur?
Most are triggered less than 50 miles
(80 kilometers) from Earth’s surface. Shallower earthquakes
have more damage potential, but a temblor’s destruction also
depends largely on rock and soil conditions as well as
93. Where are
the oldest rocks on Earth found?
Since the ocean floor is being
continually regenerated as the continental plates move
across Earth’s surface, the oldest rocks on the ocean floor
are less than 300 million years. In contrast, the oldest
continental rocks are 4.5 billion years old.
percentage of the world’s fresh water is stored as glacial
70 percent. And if you had to replace it all, you’d need 60
years of the entire globe’s rainfall, and then you’d have to
figure out a way to freeze it all.
95. What is the
largest alpine lake in North America?
Lake Tahoe on the California-Nevada
border has a 105,000-acre surface, holds 39 trillion gallons
of water, and is almost 1,600 feet (488 meters) deep.
96. Have there always been
Not as we know them today. Many
scientists figure Earth began as one huge continent — dry as
a bone. Water was delivered in comets, the thinking goes,
and the oceans developed. Much more recently, all the
world’s land masses were huddled into one supercontinent
called Pangaea. It began to break up about 225 million years
ago, eventually fragmenting into the continents as we know
97. How much volcanic ash can fall in
can only give an example. During the nine-hour period of
most vigorous activity on May 18, 1980, Mount St. Helens
dumped more than 540 million tons of ash over an area of
more than 22,000 square miles (56,980 square kilometers). It
was the most destructive volcanic eruption known to occur in
the United States. Fifty-seven people were killed by the
eruption including USGS scientist David Johnston, who was at
a monitoring site 5 miles (8 kilometers) from the volcano.
An estimated $1 billion damage was caused by the eruption,
through mudflows and landslides as well as what fell from
98. What is feldspar?
A better question might be, “Who but
a geologists could love feldspar?” It happens to be the most
common mineral in Earth’s crust. But I couldn’t find
anything about it that most of us really need to know.
99. What are the
most extreme locations in the United States, compasswise?
This one is a bit tricky, and as it
turns out three or even four of the answers may catch you
The westernmost point is the aptly
named West Point of Amatignak Island, Alaska. The
northernmost point is Point Barrow, Alaska. The southernmost
point is the southern tip of the island of Hawaii. The
easternmost point — go ahead, take a guess! — is Pochnoi
Point at Semisopochnoi, Alaska. Huh? Look at a world map.
The tip of the Aleutian Islands lies east of the 180-degree
longitude line — the International Dateline — putting
Pochnoi Point barely but officially in the Eastern
100. If you were to arrange Earth,
the moon and Mars like Matryoshka nesting dolls, how would
they be ordered?
Mars would nest inside Earth, and the
moon would fit neatly inside Mars. Earth is about twice as
big as Mars, which is about twice as big as the Moon.
101. Will Earth
always be here?
Astronomers know that over the next
few billion years, the sun will swell so large as to envelop
Earth. If we’re still here, we’ll probably fry and the
planet will be vaporized. There’s a chance, however, that
the changing mass of the sun will cause Earth to move into a
more distant and pleasant orbit. One mathematical
calculation shows it would be theoretically possible for
humans to engineer such a move before it’s too late.