Author: Axotl

Grasshopper Mouse

The grasshopper mouse, belonging to the genus Onychomys, is a fascinating creature known for its unique behaviors and adaptations. Here’s a detailed overview of its natural history:

Physical Description

  • Size: Small rodents, typically around 4 to 5 inches in body length, with an additional 1 to 2 inches of tail.
  • Appearance: They have a robust body, short tails, and large ears. Their fur is generally grayish-brown on the back and white on the belly.

Habitat

  • Geographic Range: Found in North America, particularly in the arid and semi-arid regions of the western United States and Mexico.
  • Preferred Environment: Grasshopper mice inhabit deserts, scrublands, and prairies. They are well-adapted to dry environments and can be found in areas with sparse vegetation.

Behavior

  • Nocturnal Lifestyle: These mice are primarily nocturnal, coming out to hunt and forage at night.
  • Territoriality: Grasshopper mice are highly territorial and aggressive. They establish and defend territories vigorously.

Diet

  • Carnivorous Diet: Unlike many other rodents, grasshopper mice are primarily carnivorous. They feed on insects, other small invertebrates, and even small vertebrates.
  • Specialization: They are named for their tendency to prey on grasshoppers, but their diet can also include beetles, scorpions, spiders, and even other mice.
  • Hunting: Known for their hunting prowess, they are sometimes called “scorpion mice” due to their ability to hunt and consume scorpions, showing resistance to the venom.

Vocalizations

  • Unique Calls: Grasshopper mice are known for their high-pitched, wolf-like howls, which they use to communicate with each other, especially to mark territory.

Reproduction

  • Breeding Season: Typically breed from spring through late summer.
  • Litter Size: Females give birth to 2 to 6 young after a gestation period of about 30 days.
  • Parental Care: The young are weaned after a few weeks and reach maturity at around 2 to 3 months.

Adaptations

  • Water Conservation: Adapted to arid environments, grasshopper mice obtain most of their water from the food they eat and have efficient kidneys to conserve water.
  • Venom Resistance: They have developed a resistance to the venom of scorpions, allowing them to prey on these arachnids without harm.

Ecological Role

  • Predator Control: By preying on insects and other small animals, grasshopper mice help control the populations of these species in their habitats.
  • Indicator Species: Their presence and health can be indicators of the ecological balance in their environment.

The grasshopper mouse’s unique dietary habits, vocalizations, and behaviors make it a remarkable example of adaptation to harsh environments, playing a crucial role in the ecosystems they inhabit.

Comparative Geomorphology

Here’s a comparison between the geomorphology of the Funeral Mountains – Greenwater Valley subsection and the second geomorphological description:

Geomorphology
Funeral Mountains and Greenwater Valley

  • Landforms: Steep to very steep mountains and valleys, with very gently to moderately sloping alluvial fans, nearly level basin floors, and dry lake beds.
  • Orientation: Mountains align north-south or north-northwest.
  • Elevation Range: About 1,000 feet to 6,703 feet on Pyramid Peak, with many peaks over 5,000 feet.
  • Geomorphic Processes: Mass wasting, fluvial erosion and deposition, and eolian deflation and deposition.

Geomorphology

Geomorphology is the scientific study of landforms and the processes that shape them, including their origin, evolution, and spatial distribution.

Geomorphology
Lucerne and Johnson Valleys

  • Landforms: Steep mountains, moderately steep hills, gently to moderately sloping pediments and alluvial fans, nearly level basin floors, and dry lake beds. Presence of “badlands” on eroded Miocene nonmarine sedimentary rocks.
  • Orientation: The hills’ general orientation is less straightforward than the major faults, which trend northwest.
  • Elevation Range: About 1,600 feet up to 4,873 feet in the Granite Mountains, 5,525 feet in the West Ord Mountains, 6,309 feet in the East Ord Mountains, and 5,878 feet in the Rodman Mountains.
  • Dry Lake Beds: Includes Lucerne, Soggy, Melville, Galway, Emerson, and Deadman Lake.
  • Geomorphic Processes: Mass wasting, fluvial erosion and deposition, and eolian deflation and deposition.
Greenwater Valley, Death Valley National Park

Comparison

  • Landforms: Both regions feature steep mountains and valleys, alluvial fans, basin floors, and dry lake beds. However, the second description includes pediments and mentions “badlands,” which are not noted in the Funeral Mountains – Greenwater Valley description.
  • Orientation: The Funeral Mountains – Greenwater Valley mountains align north-south or north-northwest, while the hills in the second description have a less clear orientation than the major northwest-trending faults.
  • Elevation Range: The Funeral Mountains – Greenwater Valley has a broader elevation range, reaching higher peaks (up to 6,703 feet), whereas the second area reaches 6,309 feet in the East Ord Mountains.
  • Dry Lake Beds: The second description specifies several large dry lake beds by name, which are not mentioned in the Funeral Mountains – Greenwater Valley description.
  • Geomorphic Processes: Both regions experience similar geomorphic processes, including mass wasting, fluvial erosion and deposition, and eolian deflation and deposition.

In summary, while both regions share common geomorphic features and processes, they differ in specific landform characteristics, elevation ranges, and the presence of features such as “badlands” and named dry lake beds.

Geologic Diversity

When someone mentions they are a geologist, it’s easy to assume that all geologists do the same thing. However, geology is a diverse and multifaceted field, encompassing a wide range of specialties. Each geologist may focus on different aspects of the Earth’s structure, materials, processes, and history. Here’s a more detailed look at the various types of geology and the distinct roles that geologists might have:

Types of Geology

  1. Structural Geology: Geologists in this field study the architecture and processes responsible for the deformation of the Earth’s crust. They analyze faults, folds, and rock formations to understand tectonic movements and stress patterns.
  2. Petrology: Petrologists examine the origin, composition, and structure of rocks. They specialize in:
    • Igneous Petrology: Focuses on rocks formed from magma or lava.
    • Sedimentary Petrology: Studies rocks formed by the accumulation of sediments.
    • Metamorphic Petrology: Investigates rocks transformed by heat and pressure.
  3. Mineralogy: Mineralogists study minerals, including their structure, properties, classification, and distribution. They identify and analyze mineral compositions in various geological contexts.
  4. Geochemistry: Geochemists explore the chemical composition of Earth materials and the chemical processes occurring within and on the Earth’s surface. They study element cycles and mineral interactions.
  5. Geomorphology: Geomorphologists study landforms and the processes that shape them. They analyze erosion, weathering, and sediment deposition to understand landscape evolution.
  6. Sedimentology: Sedimentologists focus on sediments and sedimentary rocks, including their formation, transport, and deposition. They study sedimentary environments like rivers, lakes, and oceans.
  7. Paleontology: Paleontologists study fossils and ancient life forms to understand the history of life on Earth. They analyze fossil records to reconstruct past ecosystems and evolutionary trends.
  8. Volcanology: Volcanologists study volcanoes, volcanic processes, and volcanic rocks. They monitor volcanic activity and assess eruption risks.
  9. Seismology: Seismologists study earthquakes and the propagation of seismic waves through the Earth. They analyze seismic data to understand earthquake mechanics and predict future events.
  10. Geophysics: Geophysicists use physical methods to study the Earth’s interior and its physical properties. They specialize in:
    • Seismic Geophysics: Uses seismic waves to map the Earth’s interior.
    • Magnetic Geophysics: Studies the Earth’s magnetic field and anomalies.
    • Gravitational Geophysics: Examines variations in the Earth’s gravitational field.
  11. Hydrogeology: Hydrogeologists study groundwater, its distribution, movement, and quality. They analyze aquifers and manage water resources.
  12. Engineering Geology: Engineering geologists apply geological knowledge to construction and environmental management engineering practices. They assess ground stability and risks for infrastructure projects.
  13. Environmental Geology: Environmental geologists focus on human interaction and the geological environment. They address natural hazards and resource management to mitigate environmental impacts.
  14. Economic Geology: Economic geologists study materials for financial and industrial purposes, such as minerals, oil, and gas. They explore and develop natural resources.
  15. Planetary Geology: Planetary geologists study the geology of other celestial bodies, such as moons, planets, and asteroids. They analyze surface features and geological processes beyond Earth.

Each type of geologist brings unique expertise to their field, contributing to a comprehensive understanding of the Earth’s dynamic systems. Understanding these distinctions helps us appreciate geologists’ specialized skills and knowledge of various challenges and projects.

Summary

Geology is a diverse field with various specialties. Structural geologists study Earth’s crust deformation, while petrologists focus on rock origins and types. Mineralogists analyze minerals, and geochemists explore Earth’s chemical processes. Geomorphologists study landforms, sedimentologists examine sediments, and paleontologists investigate fossils. Volcanologists monitor volcanic activity, seismologists study earthquakes, and geophysicists use physical methods to probe Earth’s interior. Hydrogeologists focus on groundwater, engineering geologists apply geology to construction, and environmental geologists manage natural hazards. Economic geologists explore resources like minerals and oil, and planetary geologists study celestial bodies. Each specialty offers unique insights into Earth’s processes and history.

Parietal Eye

The parietal eye, also known as the third eye, is a part of the pineal gland and is found in some species of reptiles and amphibians. It is a photosensitive organ located on the top of the head and is capable of detecting light and dark. Here are some key points about the parietal eye:

  1. Location and Structure: The parietal eye is situated in the parietal area of the brain, on the top of the head, and it is visible as a small, light-sensitive spot in some reptiles and amphibians.
  2. Function: The parietal eye’s primary function is to detect changes in light intensity, helping the animal regulate its circadian rhythms and hormone production. It can also influence basking, thermoregulation, and seasonal reproduction.
  3. Presence in Species: The parietal eye is found in various species of reptiles, such as some lizards (like iguanas) and tuataras, as well as some species of amphibians and fish. It is not present in birds or mammals.
  4. Evolutionary Aspect: The parietal eye is considered an ancient feature in vertebrate evolution, reflecting an early adaptation to environmental light changes.
  5. Comparison with Pineal Gland: While the parietal eye is light-sensitive, the pineal gland in other vertebrates (including humans) receives light information indirectly through the eyes and the brain. Both structures are involved in regulating circadian rhythms and reproductive cycles.

In summary, the parietal eye is an intriguing evolutionary feature that aids certain reptiles and amphibians in detecting environmental light and regulating physiological functions.

The Parietal Eye: Nature’s Light Sensor

The parietal eye, often called the third eye, is a fascinating feature found in some reptiles and amphibians. This photosensitive organ, located on the top of the head, plays a crucial role in detecting light and dark and aids in regulating various physiological processes.

Structure and Location

The parietal eye is situated in the parietal area of the brain and is visible as a small, light-sensitive spot. Unlike the primary eyes, which detect images, it acts as a direct light sensor. This organ is found in certain lizards (including iguanas), tuataras, and some amphibians and fish. Birds and mammals, however, do not possess this feature.

Function and Role

The primary function of the parietal eye is to detect changes in light intensity, helping the animal maintain its circadian rhythms and regulate hormone production. This detection influences behaviors such as basking, thermoregulation, and seasonal reproduction. By sensing light, the parietal eye helps these animals adapt to their environment, optimizing their physiological and behavioral responses.

Evolutionary Significance

The presence of the parietal eye is an ancient adaptation, reflecting early vertebrate evolution. It showcases how animals have developed specialized organs to respond to environmental changes. While the parietal eye is a direct light sensor, other vertebrates, including humans, rely on the pineal gland for similar functions. The pineal gland receives light information indirectly through the eyes and brain, playing a key role in regulating circadian rhythms and reproductive cycles.

Conclusion

The parietal eye is a remarkable evolutionary feature that underscores the diversity of adaptations in the animal kingdom. By detecting light and dark, it enables reptiles and amphibians to finely tune their behaviors and physiological processes to their environments, ensuring their survival and reproductive success.

Summary

The parietal eye, or third eye, is a light-sensitive organ found in some reptiles and amphibians, situated on the top of the head. It detects changes in light intensity, aiding in regulating circadian rhythms, hormone production, and behaviors like basking and thermoregulation. Present in species such as lizards, tuataras, and some amphibians, this ancient adaptation highlights early vertebrate evolution. Unlike the parietal eye, the pineal gland in other vertebrates receives light information indirectly through the eyes and brain. This unique feature helps these animals optimize their responses to environmental changes, ensuring survival and reproductive success.

Dune Saltation

Dune saltation is a key process in the formation and movement of dunes. It involves the hopping or bouncing movement of sand grains across the surface, driven by wind. Here’s a detailed explanation:

Dune Saltation Process

  1. Initiation: Wind speeds reach a threshold where they can lift sand grains from the ground. This threshold varies depending on the size and weight of the grains, as well as the wind speed and direction.
  2. Lift-off: Sand grains are lifted into the air by the wind. The initial lift is usually caused by the impact of other grains, which creates a chain reaction.
  3. Transport: Once airborne, the grains are carried by the wind. They travel a short distance before falling back to the ground due to gravity.
  4. Impact: When the grains land, they can dislodge other grains, causing them to lift off and continue the saltation process. This impact also leads to the erosion and smoothening of the surface.
  5. Repetition: The cycle of lift-off, transport, and impact continues, causing the sand grains to move in a series of short hops or bounces.

Factors Influencing Saltation

  • Wind Speed: Higher wind speeds increase the distance and height of saltation.
  • Grain Size: Smaller grains are more easily lifted and carried by the wind, while larger grains require stronger winds.
  • Surface Conditions: Smooth surfaces allow for easier saltation, while rough surfaces can trap grains and reduce movement.
  • Moisture: Moisture in the sand can cause grains to stick together, inhibiting saltation.

Impact on Dune Formation

  • Dune Shape: Saltation contributes to the growth and movement of dunes. The continuous movement of sand grains causes dunes to migrate toward the prevailing wind.
  • Sorting of Grains: Saltation can lead to sorting grains by size, transporting finer grains further than coarser ones.
  • Erosion and Deposition: Saltation causes erosion and deposition, shaping the landscape and forming various dune structures, such as crescent-shaped barchan and linear dunes.

Understanding dune saltation is crucial for studying desert geomorphology and predicting changes in dune landscapes.

Dune saltation is the wind-driven process where sand grains are lifted, transported, and deposited in a series of hops. Wind lifts grains into the air, which then travel short distances before falling back, dislodging other grains upon impact. This cycle causes sand to move and shapes dunes. Wind speed, grain size, surface conditions, and moisture influence saltation. Higher wind speeds and smaller grains increase movement, while moisture and rough surfaces reduce it. Saltation contributes to dune formation, migration, and sorting of grains by size, playing a crucial role in desert geomorphology.

Difference between standard and narrow gauge railroads

https://mojavedesert.net/railroads

SP Standard Gauge Engine No. 3203 and Narrow Gauge Engine No. 18 at Owenyo in 1951 – OwensValleyHistory.com

The primary difference between standard gauge and narrow gauge railroads lies in the distance between the two rails, known as the gauge.

Standard Gauge

  1. Definition: Standard gauge is a rail gauge with a distance of 4 feet 8.5 inches (1,435 mm) between the inside edges of the rails.
  2. Prevalence: It is the most widely used rail gauge worldwide, found in approximately 60% of all railway lines.
  3. Advantages:
    • Interchangeability: Standard gauge allows for seamless interchange of rolling stock and locomotives across different regions and countries using the same gauge.
    • Stability and Speed: Standard gauge tracks provide a stable and smooth ride, making them suitable for high-speed trains.
    • Infrastructure: Standard gauge railways often have more extensive infrastructure and better connectivity due to their widespread use.

Narrow Gauge

  1. Definition: Narrow gauge railroads have a rail distance smaller than the standard gauge. Common narrow gauges include 3 feet 6 inches (1,067 mm), 3 feet (914 mm), and 2 feet (610 mm).
  2. Prevalence: Narrow gauge railroads are less common globally but are often used in specific regions, industries, or for particular purposes.
  3. Advantages:
    • Cost-Effective: Narrow-gauge railways are generally cheaper to construct and maintain, making them ideal for regions with challenging terrain or lower traffic volumes.
    • Tighter Curves: Narrow gauge tracks can handle tighter curves and steeper gradients, making them suitable for mountainous or rugged areas.
    • Flexibility: They are often used in industries such as mining, logging, or agriculture, where flexibility and lower costs are more critical than speed and capacity.

Applications

  • Standard Gauge: Used in most major rail networks, including passenger services, high-speed rail, and heavy freight operations.
  • Narrow Gauge: Found in specialized environments such as mountain railways, industrial railways, heritage railways, and some regional lines.

Examples

  • Standard Gauge: Most North American rail networks.
  • Narrow Gauge: The Carson Colorado Railroad (3 feet gauge)

In summary, while standard gauge railroads offer advantages in interoperability, stability, and infrastructure development, narrow gauge railroads provide cost-effective solutions and greater flexibility in challenging terrains or specialized applications.

https://mojavedesert.net/railroads/carson-and-colorado

Bear Lake, Baldwin Lake and Big Bear Lake

In the summer of 1845, Benjamin D. Wilson, who owned part of the interest in the Jurupa Rancho, the site of the present city of Riverside, led a troop of Calvary in search of cattle rustlers.

Setting out from San Bernardino Valley, he divided his command. Most of the men he sent through Cajon Pass, keeping only 22 Mexican troopers with him to follow a trail across the mountains. Two days later, Wilson and his men reached the lake, where they sighted scores of grizzly bears.

Big Bear Lake

Most of the soldiers had been vaqueros. They formed in pairs and drew reatas, each pair attacking a bear. One looped a rope around the bear’s neck; his companion roped the same bear by a hind foot. Then, the men drew apart to stretch the rope taut and hold the bear a prisoner. They bagged and skinned eleven bears, stretched their hides, and continued across the mountains to join the rest of the command on the desert at Rancho Las Flores, on the Mojave River.

Here, the reunited party engaged Indians in a fight, after which Wilson and his 22 vaquero-troopers returned home by the lake. They again found the place overrun with bears, and the same 22 soldiers brought in eleven more bears—enough to give them a bear rug apiece as a trophy. It was then that Wilson gave the little body of water the name Bear Lake.

Years later, the name was changed to Baldwin Lake. The name survives, however, in Big Bear Lake, which was created at the site of the Talmadge Ranch in 1884, when a dam was built to provide a constant water supply for the Redlands District.

–
Adapted from ~ Pioneer Tales of San Bernardino County – WPA – 1940.

Exercise Desert Strike, May 1964

Mojave Desert Megaphone – A Monumental Legacy

In May 1964, the United States conducted Exercise Desert Strike, one of the most extensive military exercises during the Cold War. It involved over 100,000 military personnel. The primary objectives were to evaluate operational readiness, test conventional and nuclear forces integration, and improve command and control capabilities. The exercise was carried out in multiple phases, beginning with conventional warfare tactics and escalating to simulated nuclear warfare. This tested the troops’ adaptability and response to high-stress scenarios.

Remote Calzona Camp – Colorized

Despite meticulous planning and rigorous training, the exercise was marred by the tragic loss of 24 men. This underscores the inherent dangers and high stakes of large-scale military operations.

Map showing war zone

Key outcomes of Exercise Desert Strike included a comprehensive assessment of the U.S. military’s strengths and weaknesses. In addition, it validated cutting-edge technologies and significantly improved communication and nuclear warfare strategies. The exercise profoundly impacted subsequent military strategies, contributing to Cold War-era defense policies and nuclear deterrence.

Exercise Desert Strike remains a crucial event in armed forces history, highlighting the importance of preparedness and realistic training in maintaining national security. This exercise’s legacy continues to influence military planning and operations, proving the critical role military exercises have in safeguarding the nation. The fatalities during the exercise are a poignant reminder of the sacrifices made to pursue military excellence and national security.

A lasting relic of this period is a megaphone mounted on a rocky hill, symbolizing Exercise Desert Strike’s monumental legacy. This relic is a powerful reminder of the sacrifices necessary to defend our beautiful country. It represents the enduring commitment to national defense and the high price of freedom. It embodies the spirit of vigilance and dedication that inspires and guides military preparedness and strategic planning today.

Click the photo for the Mojave Desert Megaphone

Mojave Desert Megaphone

Military in the Mojave

East Mojave Desert

Mojave National Preserve

The Pacific Crest Trail: A Journey from Cajon Pass to Wrightwood

The Pacific Crest Trail (PCT), stretching over 2,650 miles from Mexico to Canada, offers hikers an unparalleled experience of diverse landscapes and challenging terrains. One of the captivating sections of this trail is the journey from Cajon Pass to Wrightwood in Southern California. This 27-mile segment within the San Gabriel Mountains presents an invigorating mix of natural beauty, physical challenge, and serene solitude.

Setting Out from Cajon Pass

Cajon Pass, located at an elevation of approximately 3,000 feet, marks the starting point for many hikers embarking on this segment of the PCT. The pass, intersected by major highways and railroads, is a bustling gateway to the wilderness beyond. As hikers leave behind the urban cacophony, they are greeted by the rugged charm of the San Bernardino National Forest.

The initial ascent from Cajon Pass is gradual, allowing hikers to acclimate to the elevation change while enjoying sweeping views of the surrounding valleys. This portion of the trail is characterized by its diverse flora, ranging from chaparral shrubs to the majestic Jeffrey pines. Wildlife sightings, including mule deer and various bird species, are common, offering a glimpse into the region’s rich biodiversity.

Climbing into the San Gabriels

As the trail progresses, the terrain becomes increasingly challenging, with steeper inclines and rocky paths. Hikers often find themselves navigating narrow switchbacks that test their endurance and resolve. However, the reward for this effort is the breathtaking vistas that unfold at higher elevations. The panoramic views of the Mojave Desert to the north and the Los Angeles Basin to the south are nothing short of spectacular.

One of the notable landmarks along this stretch is Silverwood Lake, a man-made reservoir that provides a refreshing respite for weary travelers. The lake’s shimmering waters, set against the backdrop of rolling hills, create a picturesque scene that beckons hikers to pause and rejuvenate. This area is also a popular spot for camping, offering a chance to experience the tranquility of the wilderness under a starlit sky.

Approaching Wrightwood

The final leg of the journey to Wrightwood is marked by a gradual descent into the quaint mountain town. Wrightwood, situated at about 6,000 feet, is a welcoming destination for PCT hikers. The town’s rustic charm, friendly residents, and well-stocked amenities provide a much-needed break from the rigors of the trail.

Wrightwood’s proximity to the Angeles National Forest means that hikers can continue to explore the area’s natural beauty even after completing this segment of the PCT. Popular activities include visiting the nearby Grassy Hollow Visitor Center, learning more about the local flora and fauna, and tackling the challenging ascent to Mount Baden-Powell, one of the highest peaks in the San Gabriel range.

Reflection on the Journey

The trek from Cajon Pass to Wrightwood is more than just a physical journey; it is a transformative experience that tests and strengthens the hiker’s spirit. The changing landscapes, from arid desert vistas to lush forested slopes, mirror the inner journey of growth and discovery. Each step taken on this trail is a step towards understanding nature’s profound beauty and resilience.

In conclusion, the Pacific Crest Trail segment from Cajon Pass to Wrightwood offers a unique blend of natural splendor, physical challenge, and serene solitude. It is a journey that leaves an indelible mark on those who undertake it, reminding them of the wilderness’s enduring allure and strength of the human spirit.