Landforms
Coastline
• White-chalk cliffs
studded with
beech trees form
the dramatic
coastline of
Rugen Island,
Germany.
Crashing waves
from the Baltic
Sea sculpted the
400-foot (120meter) precipices
of the island's
eastern shore.
Limestone Cliffs on Coastline
Coastline
Coastline
• These unique
sandbank formations
in the Baltic Sea
near Germany were
formed about 6,000
years ago when
seawaters flooded
Germany, fashioning
islands, sandbanks,
and peninsulas from
hilltops of previously
dry land. Today,
Germany's unique
offshore landscape
is part of
Vorpommersche
Boddenlandschaft
National Park.
Coastal Tunnels
Coastal Tunnels,
Victoria, Australia
• Surf froths around the
wind-and-watereroded coastal tunnels
in southwestern
Australia's Port
Campbell National
Park. Retreating tides
have left jagged
limestone formations
around the park's
coastline, giving the
area its historical
notoriety as a ships'
graveyard.
Coastal Sea Stacks
Sea stacks, like this
one shaped like
the prow of a
ship in Cape
Kiwanda State
Park, Oregon, are
chunks of
isolated rock
resistant to
erosion. They
start as part of a
headland or sea
cliff connected to
land. Smashing
waves erode the
softer rock,
leaving harder
rock behind in
the form of sea
stacks.
Basalt Columns
• Towering in close
symmetry, these
basalt columns near
Fingal’s Cave form
the base of the
Scottish island of
Staffa. The columns
formed when
cooling lava flows
met bedrock and
the region’s cold
weather. The island
contains three main
caves.
Ocean Tides
• Ocean tides
comb the waters
of coastal Alaska
into fanciful
eddies and
whorls. The ebb
and flow of tides
help sculpt an
array of
landforms on
coasts
worldwide,
including spits,
barrier islands,
and dunes.
Island
•
Surf hits turf
on the
coastline of the
Chandeleur
Islands.
Arranged in a
crescent along
the
southeastern
coast of
Louisiana, the
barrier islands
are Louisiana's
first line of
defense from
storm damage.
The surging
waters of
Hurricane
Katrina
submerged half
of the low-lying
islands.
Bora Bora (Island)
Blue Hole Reef
Lake
Granite Outcrops in a Lake
• Ancient granite
outcrops reflect in the
still water of Sylvan
Lake in South Dakota's
Custer State Park as a
lone fisherman awaits
a nibble. Geologists
calculate that the
park's granite, into
which the sculptures at
nearby Mount
Rushmore were
carved, are about 1.7
billion years old,
making it some of the
oldest rock in North
America.
Mountains
• The jagged
peaks of
Antarctica's
Filchner
Mountains rise
in the distance
as an intrepid
mountaineering
team makes
camp on an ice
field.
Mountain Climbers
Mountain
• A delicate
necklace of snow
melts from the
summit of
Tanzania's highest
peak, Mount
Kilimanjaro. Global
warming is
changing the face
of mountains
worldwide,
eliminating
snowcapped
peaks and giving
birth to surging
melt-fed rivers.
Volcanoes
• In Hawai'i
Volcanoes
National Park,
Kilauea erupts
sending lava high
into the air. This
molten rock comes
from deep within
the Earth, where
residual heat from
the planet's
formation
combines with heat
from the gradual
decay of
radioactive
elements trapped
below.
Caves
•
Lava-tube caves, like this
one in California's Lava
Beds National Monument,
are found throughout the
world. These unique
underground structures
form during long-lasting
lava flows. As lava moves
through a channel,
overflows build natural
levees along the sides,
which can eventually
connect and harden,
forming a canopy. Just as
a winter stream continues
to flow beneath its ice cap,
lava continues to move
under this roof. When flow
from the source stops, the
remaining lava moves
through to the end, leaving
a hollow tube, often large
enough to walk through.
Caves
• A spelunker in a
glacier cave in
Greenland gazes
upon colors and
shapes that look
more like a
swirling galaxy
than a cave
formation. The
otherworldly
contours of this ice
chamber were
formed by the heat
of a geothermal
spring
Caves
•
Looking like the set of
a science fiction
movie, China's Reed
Flute Cave is bathed
in purple-blue light.
Created by an
underground river
more than a half
million years ago, this
highly accessible
karst formation is one
of the region's most
popular tourist
attractions. But
during World War II
the cave served a
different purpose—it
doubled as an air raid
shelter.
Caves
Desert Badlands
• A storm passes
over Yellow
Mounds Overlook
in South Dakota’s
Badlands, casting
light and shadow
below. Although
the region’s name
derives from the
Oglala Sioux
words mako sica
or "land bad," the
Badlands
showcase the
powerful effects of
wind and water
and contain fossil
beds dating to 35
million years ago.
Desert Badlands
Desert
•
Towers of salt and a
riverbed colored by
crystallized salt
create an
otherworldly
landscape in
Ethiopia’s Danakil
Desert. Sitting more
than 300 feet (90
meters) below sea
level, with
temperatures
reaching 120
degrees Fahrenheit
(49 degrees
Celsius), local
inhabitants prize the
Danakil for one
thing: its salt
deposits.
Desert Plateau
Desert
• Massive,
disorderly rock
formations jut
from the
orange
Saharan sand
of Chad's Ouri
Valley. This
desert valley
is bordered by
the Tibesti
Mountains.
Wind Erosion in the Desert
Desert
Sand Dunes
Sandstone Swirls
Tufa
•
With the snowdraped Sierra
Nevada as a
backdrop, unique
erosion formations
called sand tufa
stand like giant
cauliflower stalks in
a dry Arizona lake
bed. Before this
alkaline lake went
dry, tufa formed
when a freshwater
spring percolated
from below and
formed calcium
carbonate deposits.
When the lake's level
dropped, these
fragile formations
surfaced, and wind
went to work
removing the sand
beneath the
deposits.
Anticline (Plate Tectonics)
• Raplee Ridge,
part of the
Monument
Upwarp in
southeastern
Utah, is a
long, narrow,
folded
anticline that
formed about
70 million to
50 million
years ago.
Plate Tectonics
•
In the Persian Gulf, two
tectonic plates collide.
The Arabian plate (lower
left) is running up on
the Eurasian plate
(upper right). The
Persian Gulf (top) and
the Gulf of Oman
(bottom) were once the
site of a rift, a place
where two plates pull
apart from each other,
and the Indian Ocean
filled in the widening
gap between the two
plates. However, the
process then reversed,
and about 20 million
years ago, the gulf
began to close up. The
collision of the two
continental plates gives
Iran its mountainous
terrain.
Glacier
• The Bernard
Glacier in
Alaska's Saint
Elias Mountains
looks like a huge
alpine highway.
Glaciers are
slow but highly
effective
shapers of the
land, essentially
carrying away
anything in their
path—from soil
and rocks to hills
and even the
sides of
mountains.
Valleys
• Glaciers carved
this steep-walled
valley, now
occupied by the
Merced River, in
California's
Yosemite
National Park.
Waterfalls
cascade down
the valley's
steep walls,
carved away by
the massive,
slow-moving
blocks of snow
and ice.
Valley Vineyard
Gorge
• A deep gorge drops
some 650 feet (198
meters) near the
abandoned city of
Araden, Crete.
Visitors can descend
into the gorge and
walk a little more than
4 miles (6.4
kilometers) to the
Mediterranean Sea. In
addition to
magnificent scenery,
the gorge provides a
2,460-foot (750meter) descent to the
sea.
Colorado River Canyon
•
The red of cactus
blooms pops in a
Grand Canyon
valley. Cut by the
Colorado River over
millions of years,
the Grand Canyon
is considered one
of the finest
examples of aridland erosion in the
world. The
immense canyon is
277 miles (446
kilometers) long
and averages 4,000
feet (1,200 meters)
deep, but it is only
15 miles (24
kilometers) across
at its widest.
Colorado River
•
Water rushes around
rocks as the
Colorado River
continues to cut its
way through the
Grand Canyon. It
takes two days by
foot or mule to get to
the bottom of the
Grand Canyon and
back, and at least
two weeks to
complete the journey
through the canyon
by raft. In 1963 the
Glen Canyon Dam
was completed
upstream of the
Grand Canyon,
radically changing
the flow of the
Colorado.
River Delta
• Standing in stark
contrast to the
surrounding
desert,
vegetation lines
the fertile Nile
River valley as it
runs northward
through Egypt.
The city of Cairo
is a gray
smudge visible
where the river
widens into its
fan-shaped
delta.
River Delta
Meandering River
• With Mexico on
the left and the
United States on
the right, the Rio
Grande forges a
clear barrier
between the two
countries. On the
U.S. side the
river winds
through the
Santa Elena
Canyon in Texas'
Big Bend National
Park. Towering
1,500-foot (460meter) cliffs of
solid limestone
mark the canyon.
Meandering River
• Porsmork Valley
is part of
Iceland's rich
landscape and
host to
thousands of
plant species.
Glacial valleys,
such as this one,
have wide valley
floors usually
littered with loose
rock and
boulders left
behind by the
massive moving
ice slabs.
Meandering River
• The Snake River
wends through
wooded flats in
Grand Teton
National Park,
Wyoming. A
wide, sagecovered plain,
home to bison
and moose,
stretches across
the valley to the
base of the
jagged Teton
Range, which
rises abruptly
from the valley
floor.
Meandering River
Waterfall
• A waterfall
cascades down
the sheer face of
the Grand
Canyon in
Arizona. In
addition to the
mighty Colorado
River running
through the
canyon, water—
a vital resource
in the arid
Southwest—
exists in the
form of springs,
streams, and
seeps.
Slot Canyon
•
A slot canyon scores
the Arizona desert,
just one of many
dotting the state's
border with Utah.
Slot canyons are
comparatively short
and unusually
narrow canyons that
can be several
hundred feet deep.
A region needs a
special combination
of rainfall and
geographical
features to make
slot canyons
possible. Rainwater
and snowmelt cut
and rubbed the red
rock of this region
for eons to form
these slots.
Slot Canyon
Canyon
•
Carved rock stretches
as far as the eye can
see in Canyon de
Chelly National
Monument in Arizona.
Canyon de Chelly is
unique among U.S.
national parks—it is
composed entirely of
Navajo Tribal Trust
Land, which remains
home to a Navajo
community. According
to Navajo beliefs, a
deity named Spider
Woman lived on top
of Spider Rock, the
sandstone monolith in
the foreground of this
picture. She devoured
children who
misbehaved, and
their bleached bones
turned the top of
Spider Rock white.
Plateau
•
Mount Roraima, a
tepui, or
sandstone mesa,
rises from the
clouds in
southeastern
Venezuela. These
rare 4,000-foot
(1,200-meter)
plateaus have
lured adventurers
to Venezuela's
canyonlands for
decades, and are
believed to have
inspired Sir Arthur
Conan Doyle to
write his 1912
novel, The Lost
World.
Plateau
Colorado Plateau
Plateau
Plains
•
A massive boab tree,
close relative of the
African and
Madagascan baobabs,
stands alone amid the
golden grasses of a
plain near the town of
Wyndham in Western
Australia. Much of
Western Australia's
7,800 miles (12,500
kilometers) of coastline
gives way to broad
coastal plains, such as
this one, that extend
inland to the state's
hot, dry central
plateau, known as the
outback.
Serengeti Plain
• Two zebras graze
the grassland at
dusk in Kenya's
Masai Mara National
Reserve. Every year,
the reserve's
200,000 zebras join
1.5 million
wildebeests in an
epic migration,
following the rain
more than 300 miles
(480 kilometers)
from Tanzania into
Kenya in the dry
season, then south
again to foal on the
storm-soaked
Serengeti Plain.