Civilizations
What is LIDAR?
LIDAR (Light Detection and Ranging) is a remote sensing technology that uses laser light to measure distances and create detailed, 3D maps of the Earth's surface.
How Does LIDAR Work?
A LIDAR system sends out laser beams from an airborne platform like a plane or drone. The beams bounce back after hitting the ground, and the time it takes for the light to return is measured to calculate distance.
Why Use LIDAR in the Amazon?
The Amazon is dense and difficult to explore on foot. LIDAR can penetrate the canopy and reveal what's hidden below, like ancient human-made structures.
What Did Researchers Find?
Researchers analyzed 5,315 sq. km of LIDAR data and discovered 24 previously unreported human-made earthworks, including fortified villages, across the Amazon basin.
How Much of the Amazon Was Covered?
The LIDAR survey covered only 0.08% of the total Amazon area, indicating that many more undiscovered sites could exist.
What's Next?
Researchers used the LIDAR data and other existing data to create a predictive spatial distribution model to estimate the locations and number of potential undocumented pre-Columbian sites.
Why Is This Important?
Understanding the history and extent of human activity in the Amazon can provide insights into its past civilizations and help in its current conservation efforts.
The use of LIDAR technology has opened a new frontier in the exploration of the Amazon, revealing hidden ancient civilizations and promising more discoveries in the future.
LIDAR in India: An Overview
Is LIDAR Being Used in India?
Yes, LIDAR technology is being used in various sectors in India, including forestry, agriculture, urban planning, and infrastructure development.
Key Projects
Highway Planning: LIDAR is used for road and highway planning, including the ambitious Bharatmala project.
Forest Mapping: The technology helps in assessing forest cover, biomass estimation, and wildlife habitat mapping.
Construction: LIDAR is used in the planning and construction of large infrastructure projects like dams and railways.
Urban Planning: Cities use LIDAR data for better land use planning and disaster management.
Coastal Studies: LIDAR helps in studying coastal erosion and planning for flood control.
Challenges/
Data Accessibility: High-quality LIDAR data is often expensive and not easily accessible for all sectors.
Technical Expertise: The technology requires specialized skills for data interpretation.
Future Prospects
With the increasing availability of drones and advancements in LIDAR technology, its applications are expected to grow in various sectors in India.
LIDAR technology is gradually gaining traction in India, offering precise data that can significantly aid in planning and development across multiple sectors.
Confirming Human Presence During Last Glacial Maximum: The Ancient Footprints of White Sands
Researchers used radiocarbon and optically stimulated luminescence dating methods to confirm the age of ancient human footprints found in White Sands National Park. The study shows that the footprints date back to between 23,000 and 20,000 years ago, proving human presence in southern North America during the Last Glacial Maximum.
Details:
Radiocarbon (Carbon14): A way to find out how old something very old is.
Optically Simulated Luminescence: Another method to find out the age of ancient things by looking at how much light they give off.
Antiquity: How old something is.
Ancient Human Footprints: Old footprints left by people a long time ago.
White Sands National Park: A park in the U.S. where these old footprints were found.
Independent Ages from Multiple Resolved Sources: Using different ways to confirm how old something is.
23,000 and 20,000 years ago: The time when these footprints were made.
Last Glacial Maximum (LGM): The last time it was super cold and icy everywhere.
The Last Glacial Maximum (LGM) refers to the most recent period in Earth's history when the glaciers were at their thickest and took up the most land area.
This happened about 26,000 to 20,000 years ago. During this super cold and icy time, large parts of North America, Europe, and Asia were covered by ice sheets.
The climate was much colder than it is today, and this affected not just the landscape but also the plants, animals, and even human civilizations.
Understanding the LGM helps scientists learn about Earth's climate history, how glaciers move, and how dramatic climate changes can impact life on Earth.
Significance
This discovery is important because it shows that humans were in this area much earlier than we thought, even during the last big ice age. It helps us understand more about where humans lived a long time ago.
The term "Independent Ages from Multiple Resolved Sources" refers to the practice of using various methods to cross-verify the age of an ancient object or site.
This approach enhances the accuracy and reliability of the dating process. By employing different techniques, researchers can be more confident that the determined age is correct,
reducing the chances of error or bias. This multi-method validation is crucial in fields like archaeology and paleontology,
where precise dating can significantly impact our understanding of history or prehistoric life.
The methods commonly used for dating ancient objects or sites include: Radiocarbon Dating (Carbon-14): Measures the decay of carbon-14 in organic materials to estimate their age. Optically Stimulated Luminescence (OSL): Determines the last time quartz or feldspar grains were exposed to sunlight, useful for dating soil and sediments. Uranium-Series Dating: Measures the decay of uranium isotopes in calcium carbonate deposits, often used for cave formations and bones. Thermoluminescence: Used to date ancient ceramics and pottery by measuring the stored energy that is released as light upon heating. Dendrochronology: Uses tree rings to date wooden objects or to calibrate other dating methods. Stratigraphy: Examines the layering of soil or rock to determine the relative age of different layers, often used in conjunction with other methods for more accurate dating. Argon-Argon or Potassium-Argon Dating: Measures the decay of potassium to argon in volcanic rocks and minerals. Electron Spin Resonance (ESR): Measures trapped electrons in bone or tooth enamel, providing a minimum age for the sample. Amino Acid Racemization: Measures the ratio of amino acids in fossils to estimate their age. Fission Track Dating: Counts the damage tracks left by decaying uranium in minerals like zircon. These methods are often used in combination to cross-verify the age of an object or site, ensuring greater accuracy and reliability.
