Mojave Desert

Mojave Desert
Used with permission. © Darren Guenther

My family has spent some time in Arizona and California on several occasions. It has always been a lot of fun! Coming from the north it was always a challenge adjusting to the weather; Tasha loves the heat but the rest of us don't handle it quite as well. One of my favourite parts about our trips to the desert are the Prickly Pear Cacti. Did you know you can actually eat part of the Prickly Pear Cactus? And it's delicious!

Map of the Mojave Desert
Location: 
The Mojave Desert is located in the southwest of the United States. It is approximately 25,000 square miles and covers land between several other deserts, including the Sonoran Desert (to the south) and the Great Basin Desert (to the north). The Mojave Desert's western edge is bordered by three mountain ranges—the San Bernadino mountains, the San Gabriel mountains, and The Tehachapi mountains.

Joshua Tree National Park
Rennett Stowe, flickr creative commons, CC BY 2.0

The Mojave Desert is said to be one of the smallest deserts in North America. The Mojave Desert is largely located in California; small parts of the Mojave Desert are also located in Utah, Nevada, and Arizona. Death Valley, which happens to be the lowest and hottest place in all of North America, is one of the three national parks located in the Mojave Desert. The other two national parks are the Mojave National Preserve and Joshua Tree National Park.

 

Mojave Desert Landscape
Used with permission. © Darren Guenther

Landscape: 

The Mojave Desert is typically known for its Basin and Range topography. Aside from the extreme low and high elevation in the Death Valley national park, the general elevation of the Mojave Desert falls between three and six thousand feet above sea level. Death Valley contains the lowest point in the Mojave Desert, Badwater is 282 feet below sea level.

 

Mojave Desert Water Sources
James Marvin Phelps, flickr creative commons, CC BY-NC 2.0

The Mojave Desert has a landscape that makes the most of the limited precipitation it recieves. Landforms like rock pools, rivers, and washes store the water so that plants and animals can access it over time. In a lot of the areas in the Mojave region even the ground can be an excellent source of water for the desert's organisms.

The Mojave Desert contains several fascinating features. Below are some of the diverse landforms found in the Mojave Desert...

Mojave Desert Basin
James Marvin Phelps, flickr creative commons, CC BY-NC 2.0

Basin: 

A basin is sort of like a natural sink—it is an area of land that is lower than its surroundings. Basins are formed by wind or water erosion. Canyons and basins are similar in their formation, except basins tend to be much larger in size.

The Rainbow Basin is a well-known basin in the Mojave Desert. It doesn't actually look like a basin or a canyon; however, it is refered to as both by scientists and tourists. In this case the wind and water erosion has created layers of stone, forming a colorful depression in the wall of a mountain. The Rainbow Basin changes constantly when new layers of sediment are revealed by erosion or added by wind.

 

Desert Buttes
Duncan Rawlinson, flickr creative commons, CC BY-NC 2.0

Buttes: 

A butte is like a plateau with its very flat top; although, buttes are usually taller than they are wide. The shape of the butte is formed from streams eroding through a plateau. The top of a butte remains flat because it is protected by the top layer—known as the caprock. Buttes can easily be described as tall hills with steep sides that appear to stand alone.

 

Kelso Dunes
drcohn, flickr creative commons, CC BY-NC 2.0

Dunes:

Dunes are formed by wind, and are common in deserts. Sand and loose sediment is pushed up into a mound or a ridge and continues to be shaped by the wind over time. In some cases wind can carry new sand grains onto dunes to replenish them.

The largest dune field in the Mojave Desert are the Kelso Dunes. These particular dunes are formed mainly by grains of feldspar and quartz, and the mounds reach up to 600 feet above the desert floor. Interestingly, the Kelso Dunes were first created by grains of sand blown together from the Mojave River sink; however, there haven't been any new deposits of sand among the Kelso Dunes since they were originally formed.

 

Tronna Pinnacles
Kelly Mendenhall, flickr creative commons, CC BY-NC 2.0

Pinnacles:

Pinnacles are large spires of rocks which are formed when spring water combines with other bodies of water. They often collect in groups.

The Trona Pinnacles are located in the Mojave Desert and were created by groundwater and lake water mixing to form these unique rock structures. The Trona Pinnacles can be up to 43 meters in height!

 

Mojave Playas
Yathin, flickr creative commons, CC BY-NC-ND 2.0

Playas:

A playa is a dried out lake bed. Playas don't contain very much vegetation and are made up of lots of clay and silt. The ground of a playa often appears scaly and cracked because of the heat and lack of water. They are often found in the lowest and flatest area of a desert basin. Occasionally, during wet periods or near water sources, there will be a little bit of water on the surface of the playa.

Playas are a very useful way to discover the history of an area, because the features and characteristics can reveal information about a regions past and present climates.

 

Snow in the Mojave Desert
Will Dugdale, flickr creative commons, CC BY-NC 2.0

Climate:

The Mojave Desert is considered a transition desert by many, resting between the hot Sonoran Desert and the colder Great Basin Desert. The Mojave Desert can have a wide range of temperatures throughout the day. Also, there are relatively distinct seasons. In the winter temperatures can fall below 0°C, but the summer temperatures can reach an incredible 54°C, especially in the Death Valley.

The Mojave Desert recieves very little precipitation each year—approximately 250mm annually. The precipitation is usually in the form of rain; however, there is the rare possibility of snow.

 

Storm in the Mojave Desert
Justin Ennis, flickr creative commons, CC BY 2.0

Storms occur throughout the year, but autumn is said to be the most pleasant season. Winter and spring storms come from the Pacific, while the low humidity summer results in storms that draw moisture from the Gulf of Mexico. The Mojave region is bordered by lots of mountains, which create a "rain shadow". Since the Majove Desert is a rain shadow desert, many of its storms come with lots of clouds and wind but less precipitation.

 

Prickly Pear Blossom
Bryant Olsen, flickr creative commons, CC BY-NC 2.0

Plants and Animals:

Although the Mojave region is a desert and experiences very little precipitation—making it hard for organisms to sustain life—nearly two thousand plant species can be found in the Mojave desert. Most interestingly, about a quarter of these plants are specific to the Mojave Desert alone. The Joshua Tree for example cannot be found anywhere but the Mojave Desert. Species that only live in one location on Earth are known as "endemic" species.

 

Desert Horned Lizard
Yathin, flickr creative commons, CC BY-NC-ND 2.0

There are a lot of different animal species that manage to survive in the Mojave Desert despite the lack of water and sparce vegetation in some areas. Reptiles like the desert horned lizards feast on the different insects in the area while the more venomous western daimondback rattlesnake feasts on small critters. Little creatures like the kangaroo rat have to watch out for so many predators; since they are on the run in such a hot habitat, kangaroo rats don't sweat because they can't afford to lose water.

 

Desert Pronghorned Antelope
mnchilemom, flickr creative commons, CC BY 2.0

Cougars prefer to feast on larger animals when they can, but occasionally have to settle for small critters if they can't find a filling mule deer or desert pronghorn antelope. Some animals have a slight advantage from the sky; a red-tailed hawk has a much easier time avoiding predators and catching prey. Similar to the plants of the Mojave region, there are also lots of endemic animal species that are protected by the Endangered Species Act.

 

Mojave Desert Old House
Michael Dorausch, flickr creative commons, CC BY-SA 2.0

Human Presence:

There has been a long history of people in the Mojave region. Despite the consistenet presence of humans for over 20,000 years, the Mojave Desert has managed to keep a relatively natural condition because so much of the area is too difficult for humans to inhabit, due to lack of water and extreme heat. When people first arrived in the Mojave Desert the region was wetter and cooler. Native tribes used rivers and lakes like the Colorado river to sustain life. The native tribes must have been incredibly resourceful in order to live in the Mojave region; this is proven by their ability to make pottery from clay and crushed sandstone.

 

Mojave Desert Old Wagon
Mike Fisher, flickr creative commons, CC BY-NC 2.0

Later on human presence in the Mojave Desert grew because gold was discovered in Northern California. At first, the Mojave Desert was just a step along the way to mine for gold, and the travelers had to prove themselves on the path. Due to the lack of water, the heat, and the rough terrain, the Mojave Desert was a difficult route. When the gold ran out in the first mines, many of the miners and their families returned to the Mojave Desert to develop gold and silver mining towns. This cycle continued as new mines were found and then used up. The towns that the miners built would be left as ghost towns when the miners moved away.

Nowadays there are over one million people living in the Mojave Desert and even more live around it. One of the most important industry's in the Mojave Desert is actually the tourism. With so many national parks, endemic species of plants and animals, and unique landforms, lots of people travel to the Mojave Desert in order to experience the region's diversity.

 

Worksheets and Other Activities: