Bryce Canyon National Park features hoodoos and spires in a natural amphitheater,
attracting geologists and tourists alike.
Why Is It Famous?
This Utah landmark is famous for the fantastic shapes that its rock
Bryce Canyon National Park is in southern Utah on the Colorado Plateau.
The hoodoos in Bryce Canyon National
Park are the result of water repeatedly freezing and melting into vertical
cracks that existed in sedimentary rocks. Some of these hoodoos are incredibly
tall, standing higher than a 10-story building. The unique shapes include
narrow rock fins and bulging spires.
The hoodoos in their unique shapes are the result of water erosion over
time, with minimal wind involvement. Gravity and ice also played a role, in
addition to the water. Thanks to those forces and the Claron Formation’s differential
erosion, the national park has unique morphology unlike that found anywhere
else in the world.
The Colorado Plateau caught and lifted the Paunsaugunt Plateau 10 to 15
million years ago. This led to the formation of joints that let water flow in. That
water caused erosion that created gullies and rivulets, eventually creating the
deep slot canyons.
The Claron Formation in Bryce Canyon National Park contains limestone,
dolomite, mudstone, and siltstone. The undulating shapes on the hoodoos are the
result of the fact that these rock types all erode at different rates. Frost
was mostly responsible for eroding the hard siltstone, dolomite, and limestone.
The soft mudstone ran more easily. Before their erosion, the rock formations at
Bryce Canyon started developing between 144 and 63 million years ago.
Events in Time
Native Americans have been in the Bryce Canyon National Park for around
12,000 years, evidenced by worked stone artifacts. LDS Church emissaries displaced
the Paiutes during the late 1800s. Visitors started arriving at the site in the
early 1900s with 1923 seeing the official formation of the Bryce Canyon
The unique hoodoos with their fantastical shapes at Bryce Canyon
National Park in Utah are the result of water, ice, and gravity, causing
erosion on rocks that were 63 to 144 million years old.
Giant’s Causeway is a formation of large black basalt columns in Northern Ireland that appear to form steps.
Overall, the site has more than 40,000 of these interlocking columns, creating a unique appearance.
Why Is It Famous?
The unique appearance of Giant’s Causeway, with its volcanic-formed
pillars that appear to function as stepping stones, has led to its fame.
The Giant’s Causeway sits along Northern Ireland’s Causeway Coast,
where you will also find Whiterocks Beach and Dunluce Castle. This entire area
is in the County Antrim within Northern Ireland’s north coast. The closest town
is Bushmills, which is around three miles away.
The over 40,000 hexagonal columns of black basalt likely formed due to
volcanic activity around 50 to 60 million years ago. Geologists believe that
the variations in the sizes of the columns are due to the lava cooling at
different speeds. The columns line up perfectly to create stepping stones
spanning from the foot of the cliff to the sea. Most columns in the Giant’s
Causeway are hexagonal. Some also have eight, seven, five, or four sides. The
columns can be as thick as 28 meters and as tall as 12 meters.
The formation began during the Paleocene Epoch with volcanic activity. The
basalt that was molten and therefore, highly fluid spread through chalk beds to
create a lava plateau. The lava contracted as it cooled, causing fractures. Those
fractures led to cracks and the pillar-like structures.
Events in Time
According to legend,
Irish giant Fionn mac Cumhaill and Scottish giant Benandonner hated each other.
Fionn built the path to reach Scotland via stepping stones after too many
insults. Legend says that Benandonner ripped up the stepping stones, resulting
in the current Giant’s Causeway.
UNESCO declared the Giant’s Causeway a World Heritage Site in 1986, and
the Department of the Environment for Northern Ireland declared it a national
nature reserve the following year.
The Giant’s Causeway is the result of lava from 50 or 60 million years
ago and appears as a series of 40,000 hexagonal columns made of black basalt.
Cave of the Crystals is named perfectly as this is a cave filled with
gypsum crystals of unusual sizes.
Why Is It Famous?
The cave stands out in the geological world for the giant size and abundance
of selenite crystals. The largest crystal is 12 meters long with a diameter of
The Cave of the Crystals sits in the Naica Mine within Chihuahua, a
Mexican state. It sits 300 meters underground.
The large crystals within the cave likely formed due to groundwater
saturated with gypsum flowing through the caves before hot magma below heated it
and then cooled. Geologists estimate that some of the crystals are more than
500,000 years old. The smaller crystals found in the Cave of the Swords is
likely due to quicker cooling.
Geologists are unsure whether human activities in the Cave of the
Crystals have caused problems. It had been filled with water before being first
discovered, and pumping did not stop until 2017. Samples suggest that the 17
years with air exposure damaged the structure of the crystals. However,
geologists hope that the presence of water will encourage the crystals to grow
Events in Time
Penoles Mining Company first discovered
the Cave of Swords, a smaller cave filled with crystals in the location, in
1910. In 2000, the mining company pumped water out of the Cave of the Crystals
without knowing what it held. Brothers, Juan and Pedro Sanchez, were the first
to spot the giant crystals.
Research into the cave is challenging due to the incredibly high
temperatures and humidity levels. The high humidity means that fluids can
condense in the lungs of any visitor, which restricted visits to 10 minutes
before the geologists exploring the site were able to create cooling suits. In
2008 and 2009, the NASA Astrobiology Institute director entered the cave and
found microbial life forms in the crystals.
The Cave of the Crystals was discovered by accident. It features truly
massive selenite crystals that had been surrounded by water until their
discovery. Entry is no longer possible as the mining company who found the cave
no longer pumps out the water.
The San Andreas Fault is one of the world’s biggest fault lines, making
it a crucial part of any geological discussion.
Why Is It Famous?
The San Andreas Fault is famous for its incredible length, spanning
almost 1,300 kilometers. Its fame also comes from the potential damage it can
do if a major earthquake occurs.
The San Andreas Fault sits
across California, separating the North American and the Pacific tectonic
plates. It creates a line from Cape Mendocino down to the border with Mexico.
The San Andreas Fault’s history began more than 30 million years ago
with the collision of the North American and the Pacific tectonic plates. The
main section of the fault has only been around for 5 million years or so. The
San Andreas Fault is divided into Northern, Central, and Southern zones due to
This is a transform fault, so the two plates rub each other side to
side. The plates move slowly, only several inches each year. Geologists can
spot the fault at a few locations via pressure ridges and scarps, including at
the Olema Trough and the Carizzo Plain. In most cases, however, it is not
noticeable unless you pay attention to the variations in rocks on either side
of the fault line.
Events in Time
Professor Andrew Lawson from UC Berkeley first discovered the San
Andreas Fault in 1895 within its Northern Zone. He named it after the San
Andreas Valley that surrounds the fault.
In 1906, the fault made unfortunate history with the great San Francisco
Earthquake. This earthquake led Professor Lawson and others to conclude
that the fault line extends throughout southern California. Many in California worry
about the possible consequences of a future earthquake along the fault line,
especially since one has not occurred in a long time.
The San Andreas Fault runs throughout California and caused the 1906
San Francisco earthquake. It has the potential for significant future damage if
another earthquake occurs.
The lakes are dotted with over 35,000 islands. Several are small and uninhabitable, while one, Manitoulin, is the largest island in an inland body of water in the world. Lake Superior is easily the deepest, with depths maxing out at 1,333 feet. Lakes Huron, Michigan and Ontario have depths between 750 and 925 feet, while Lake Erie is considerably more shallow at just 210 feet.
As the first gateway to the West, the Great Lakes played an enormous part in the history of the United States. For the indigenous people who called their shores home for centuries, the lakes represented more than bodies of water; they were the essence of life as they knew it. The cultural impact of these lakes and the area’s earliest inhabitants colors every community within the Great Lakes Basin. Each lake has some cultural relevance or historical footnote as well.
Lake Superior was the site of one of the last and most famous shipwrecks on the Great Lakes. On November 10, 1975, the Edmund Fitzgerald sank in a storm with all 29 crew members aboard. Canadian singer Gordon Lightfoot recorded a song that memorialized this wreak.
Lake Michigan honors those who lost their lives to shipwrecks on its waters with the Straits of Mackinac Underwater Preserve. Here, divers can explore the 12 sunken ships and pay homage to those who went before them.
The Battle of Lake Erie in the War of 1812 was fought off its north shore in September 1813. The U.S. navy beat the British to reclaim Detroit.
Such a dramatic event in an area that’s geographically and politically difficult to traverse led to rampant speculation on the cause behind this explosion that decimated 500,000 acres of nearby pine forest. These wild explanations covered everything from scientific explanations like black holes to science fiction like aliens and everything in between, but they started with religion.
Scientists of varying fields proposed the theory that aliens caused the Siberian event. Theories posited that the destruction was caused by an alien spacecraft landing, crashing or even discharging an antimatter weapon. Russian engineer Aleksander Kasantsews proposed that the Tunguska event was an extraterrestrial nuclear explosion and pointed to locally recorded geographical anomalies that mimicked those of a nuclear blast.
A Black Hole
An unnamed American physicist proposed a theory in 1973 that involved miniature black holes. Seriously. The theory suggested that one of these mini black holes collided with the Earth and caused an antimatter explosion in the atmosphere. It then somehow vanished without causing any more problems.
What It Was
Although more than 40 expeditions since 1928 have returned little concrete evidence of what happened at the Tunguska event, the scientific community has concluded that the Tunguska event was caused by a cosmic object — most likely a large meteorite — that exploded before making an impact.
Despite this explanation, the mysterious event in the Siberian expanses of Russia inspired a number of artistic endeavors. Dozens of books, mostly science fiction, use it as a basis for the action in their stories. Movies, television shows and music refer to the events that took place years ago on that June morning. In fact, you can watch a History channel documentary on this event here.
Moreover, every year June 30 marks International Asteroid Day. Although not specifically meant to commemorate the Tunguska event, it happens on the anniversary of this most well-known run-in with one to help raise awareness of the danger large meteorites may pose to the Earth.
This rare and still not completely explained event foreshadows the future of humanity. As an astronomer at NASA’s Ames Research Center said, “Tunguska is the largest cosmic impact witnessed by modern humans. It also is characteristic of the sort of impact we are likely to have to protect against in the future.” Thus, the more we can learn about the Tunguska event, the better prepared we can be.
Go back to ancient times, and the original name of the Euphrates River makes complete sense.
In the original Greek and Hebrew, Euphrates means that which makes fruitful. Along with the Tigris River, the Euphrates did exactly that for ancient Mesopotamia, as irrigation from the river allowed the first city-states in history to form.
Unfortunately, the Euphrates isn’t what it once was. Issues between the three countries it flows through, Turkey, Syria and Iraq, have sapped it of its former greatness and left the river in peril in the 21st century.
How Long and Deep is The Euphrates?
When all is well, the Euphrates flows for 1,740 miles, starting in Turkey before flowing through Syria and Iraq on its way toward the Persian Gulf. The river can be as wide as about one-third of a mile and 30 to 147 feet deep in some areas. It’s formed by the joining of two rivers, the Karasu and Murat, which exist in the Armenian Highlands.
Why Is the Euphrates Important?
What made the Euphrates such a vital river was the fact that its waters made the land known as Mesopotamia fruitful. The Mesopotamians developed irrigation and brought the water from the Euphrates toward the land, allowing civilization to develop around the region’s farmland. Further success in the area came when the Assyrians and the Babylonians settled the land.
How Far is the Euphrates From the Tigris River?
It’s virtually impossible to discuss the Euphrates without bringing up its partner, the Tigris River. The two rivers are a mere 30 miles apart in some spots.
Why is the Euphrates Drying Up?
Three nations using the river as their main source of water has led to the Euphrates losing a great deal of its volume. Both Turkey and Syria have constructed dams to take water out of the Euphrates, which has left far less in the remainder of the river for Iraq.
The Middle East is also a drought-prone region, and its arid climate has prevented the Euphrates from receiving enough rain water to replenish what the area’s population takes out of it. With a mere 24 inches of rain falling per year in some spots, the river has had little chance to recover from human usage.
Mining also hurt the Euphrates in the past, as the site was once mined for minerals such as silver, lead and zinc. However, mining was abandoned in the late 1980’s, shortly before the Gulf War plunged the region into complete instability.
How Has Pollution Hurt the Euphrates?
The Middle East has been drilled for oil extensively in the past half-century as cars have become the dominant mode of transportation throughout the world. Unfortunately for the Euphrates, the oil-rich area means that the Middle East often ends up quite poor in terms of water. Not only has oil meant an increase in pollution, but the area is one of the most war-torn in the world, which has lead to the health of the river falling by the wayside.
How Many People Rely on the Euphrates?
The Euphrates River basin serves 23 million people, which has made the pollution problems and lack of water in the river a serious issue for the Middle East.
While the Euphrates was once one of the world’s great rivers that helped create civilization as we know it, the sad fact is that the river is in grave peril unless its nations can come together for a solution. The Euphrates might have given birth to civilization, but without serious action in the immediate future, civilization might be what causes its downfall.
Kilauea is one of the planet’s most active volcanoes, and it’s the youngest — about 600,000 years old — of five volcanoes on the Big Island of Hawaii.
Along with nearby Mauna Kea, Kilauea is still adding to the island’s topography, and its unique character, geologic importance and dramatic history only increase its allure.
Kilauea Geological and Geographical Details
Situated at the southeastern edge of a curving volcanic band, Kilauea was once believed to be a satellite of Mauna Kea, its much larger neighbor. However, geologists have determined that Kilauea’s magma vent and conduit system is completely separate. Known as a shield volcano of basalt composition, Kilauea has erupted in alternating cycles that are either explosive — dominated by tephra — or effusive — dominated by lava flow — for the past 2,500 years.
At its highest point, Kilauea is 4,190 feet above sea level. Measuring 1.86 miles in length by 3.11 miles in width, the caldera’s summit is 541 feet deep. Kilauea comprises 564 square miles, which is about 14% of the island’s land area.
How to Get There
The nearest airport is in Hilo, Hawaii, while the city closest to the Kilauea volcano is Kalapana.
According to geologists, 90% of Kilauea’s surface is covered by lava flows that are less than 1,000 years old, while about 20% of those flows are younger than 200 years. Meanwhile, researchers say that the oldest above-sea-level lava flows, located at the central part of the volcano’s south flank, date to between 210,000 and 280,000 years ago when they first erupted onto the floor of the ocean.
Throughout its history, Kilauea has rained destruction on the nearby settlements and towns, killing thousands.
Pyroclastic surges rained down Kilauea’s western summit area in a series of violent volcanic explosions in 1790. This was considered the deadliest eruption at that time, with human deaths estimated at more than 400 to perhaps thousands.
In 1924, on the floor of Kilauea’s summit caldera and within the Halemaumau crater, an explosive volcanic eruption occurred that hurled dense, multiton rocks more than half a mile from the crater.
In 1990, Kilauea’s current eruption period began with lava flooding the nearby village of Kalapana, destroying in excess of 900 homes during a nine-month period.
Since the start of the most recent long-duration eruptions in 1983, continuing through 2018, Kilauea has produced a cubic mile of lava and reshaped 48 square miles of land.
After the April 2018 eruption, the crater’s deepest portion is now some 938 feet beneath its previous floor.
Both Kilauea and Mauna Kea are currently ranked by the U.S. Geological Survey’s Volcano Hazards Program at a very high threat potential.
Why is Kilauea Historically Significant?
Hawaiian legend is rich with accounts of Pele, revered as the goddess of lightning, fire, volcanoes and wind, who makes her home in the Halema’umu’u crater of Kilauea. Indeed, the profuse volcanic eruptions Kilauea produces are said to be the work of the angry goddess. The name Kilauea essentially means great spreading and spewing in Hawaiian, no doubt a reference to the frequent flows of lava during the volcano’s eruptions.
In 1823, when a European missionary, Rev. William Ellis, viewed the summit, Kilauea had already been erupting for hundreds of thousands of years. This phenomenon shows no signs of abating, making the Kilauea volcano a much-monitored world hotspot that will continue to pose significant threats to the island’s people and property.
The word batholith comes from the Greek word bath and the suffix -lith, which means deep rock. It’s the perfect name for these subterranean monoliths.
How They’re Formed
The majority of these massive rocks form deep inside mountain folds that have endured faulting. These cracks and crevices create the perfect places for the magma that becomes a batholith to slip in and form new structures once it cools.
Once it’s exposed, the difference in pressure and the influence of weather removes layers with rough edges and sharp corners. The resulting rock surface is clean and rounded. This uniquely shaped structure is visible for miles.
Size & Depth
Batholiths are a minimum of 40 square miles in size. Beyond that, their size, depth and shape vary greatly depending on the factors that influenced them during their creation and emergence. Some remain smooth and rounded for years to come, others become jagged peaks. Some of these extend more than 1,000 miles.
While it was once believed that these intrusive igneous rock structures extended to unknown depths, studies conducted around 2013 proved that this may not be true. Many of these studies indicated that batholiths could be no more than 6 to 9 miles (10 to 15 km) deep.
The Significance of Batholith to Geology and Humanity
According to the United States Geological Survey conducted by the Department of the Interior, the study of batholiths is important for understanding the ecology and mineral resources of the area as well as the inherent natural hazards. For the first two areas, the feldspar and quartz composition that is nearly always present in batholiths is a treasure trove for research. Studying the damage done by the significant internal stress batholiths are subjected to can help areas prepare for earthquakes and landslides.
Sierra Nevada Range
The most well-known batholith is at the core of the Sierra Nevada mountain range. It was exposed as the mountains rose eroding the material that had covered the monstrosity for millions of years. The exposed peaks of this batholith became the jagged granite peaks of High Sierra.
The Sierra Nevada range is the largest mountain range in the contiguous United States. Furthermore, the Sierra Nevada summit Mount Whitney is the tallest peak. Other mountains within the Sierra Nevadas that are part of the batholith include Half Dome and El Capitan in Yosemite National Park.
The Sierra Nevada mountains witnessed the dawning of the California Gold Rush as hopeful miners with dreams of striking it rich rushed to its mineral-rich foothills in the early middle of the 19th century. The rush began in January of 1848 when the first gold flakes were found in American River at the base of the Sierra Nevada Mountains near Coloma, California. Soon, communities in the area were inundated by more than 4,000 of these miners. This changed the communities and California forever.
Batholiths Around the World
In addition to the Sierra Nevada range, there are lesser-known batholiths around the world. These outcroppings range in size and age with many of them containing peaks and summits that are better known than the batholith itself. In fact, most people don’t even know that the batholith exists. Regardless, the world’s batholiths include:
Egypt: Aswan Granite batholith
Ghana: Cape Coast batholith
South Africa: Darling batholith
Uganda: Mubende batholith
Antarctica: Antarctic Peninsula and Queen Maud batholiths
Siberia: Angara-Vitim batholith
India: Bhongir Fort batholith and Mount Abu
Himalaya: Gangdese, Karakorum and Trans-Himalayan batholiths
Kazakhstan: Kalba-Narym batholith
Thailand: Tak batholith
Central Asia: Tien Shan batholith
England: Cornubian and North Pennine batholiths
Ireland: Donegal and Leinster Boulder batholith
France: Mancellian batholith
Norway: Sunnhordaland and Bindal batholiths
Australia: Cullen, Kosciuszko, Moruya and New England batholiths
New Zealand: Median batholith
Argentina: Achala and Cerro Aspero batholiths
Peru: Coastal and Cordillera Blanca batholiths
This continent has a number of batholiths, which is likely due to a large number of tectonic plates that surround North America. Scientists believe these plates play a large part in not only the formation of batholiths but their emergence as well. North American batholiths include:
Bald Rock batholith
British Virgin Islands
Town Mountain Granite batholith
Golden Horn batholith
Pike’s Peak Granite batholith
Rio Verde batholith
Batholiths shape and reshape the landscapes of the world. These enormous intrusive rocks create some of the most beautiful vistas in nature. Like the Sierra Nevada range, they have a long history that changed the course of the people who live around them.
Historically, the Rio Grande might be one of the most important rivers in terms of the formation of the United States.
Today, it forms the border between the United States and Mexico, but in the 1830s, it flowed through three nations: the U.S., Mexico and what was then the independent Republic of Texas.
While Texas never actually controlled the Rio Grande as an independent republic, the river was an important part of its annexation by the United States, as Texas’ claim on the river was one step in the Lone Star State’s joining the Union.
What Other Names Does the Rio Grande Have?
Venture south of the river, and you won’t hear it referred to as the Rio Grande. Instead, Mexicans refer to it as the Rio Bravo, which translates to the furious river. If you’ve ever taken a look at the Rio Grande, the Mexican name makes perfect sense. The river is full of rapids and rocky terrain, making it impossible to navigate, and in recent years, it has seen its water supply dwindle, which compounds the situation. The Rio Grande is as deep as 59 feet in some spots, but in other areas, especially near major cities like Albuquerque, it has found itself running dry.
Why Is The Rio Grande So Important?
Following its history with Texas and the Mexican-American War, the Rio Grande has played a major role in relations between the United States and Mexico. In the early 20th century, the Rio Grande was the source of a major dispute because of the area known as the Chamizal, a square mile of land that formed when heavy rains shifted the Rio Grande slightly to the south, resulting in land that was once part of Mexico shifting to the Texas side of the river.
The nations spent 60 years locked in a bitter dispute over the land, a completely unusable portion of farmland that had nonetheless become the home of several Texans. In the 1960s, however, the United States officially ceded the land back to Mexico, and the two nations worked to construct a concrete channel to force the Rio Grande back onto its original path.
In recent years, the river has served as another point of contention as the border situation between the United States and Mexico has worsened. Attempts to build a wall on the border between the two countries have been blocked by the river, as a 1970 treaty prevents either nation from building anything that obstructs the flow of the Rio Grande.
What Problems Has the Rio Grande Faced?
Like many rivers in the 20th century, the Rio Grande has endured more than its share of pollution. Mexico and the United States have attempted to clean it in the 21st century, but the effects of dumping sewage into it during previous decades are obvious. In 2018, it was named one of the most endangered rivers in the United States, marking a major problem for New Mexico and Colorado when the river turns north from the Mexican border.
What the Rio Grande’s future holds depends on whether the Southwestern United States and Mexico can cooperate to keep the river flowing properly. Without it, water issues could become a major problem for the Western United States in the not-too-distant future.