Image source: impossiblegeology.net
Geologists use LIDAR to see and study the earth’s surface mostly in areas where trees and vegetation obscure the earth’s landscape.
The Lidar system (light detection and ranging) uses pulses of light to collect 3D information. An airplane using a laser system pointed at the ground can collect Lidar data which is used to create 3D models of the earth’s surface.
In geology, collected Lidar data can allow the study of the earth’s topology and its origin through a process known as geomorphology. It gives high-resolution imaging and an accurate view of an area by hiding the vegetation. The high-imagery of the Lidar system gives detailed information about landforms of an area that was previously unrecognizable due to dense vegetation.
How geologist use Lidar systems
1. To study volcanoes: Lidar is used to monitor volcano activity and map lahar hazards. It accurately measures the topography downstream of the volcano and determine the possible lahar travel paths, identify the dangerous zones and determines safe routes suitable for evacuation.
2. Glaciers data: Lidar technology monitors the growth and decline of glaciers in areas with huge glaciated peaks and mountain ranges. Geologists continue to monitor the glacial history to determine its effect on climate change and also identify other features like moraines and outwash channels based on the last ice age.
3. Landslides: A high-quality Lidar system is used to provide an aerial view of the earth landslides which can be obscured by the dense vegetation. Geologist uses Lidar to quickly and accurately find large tracts of land making the landslides.
4. Faults: There are countries with active fault zones both in remote areas and in major cities which can pose hazardous risks to human life. A Lidar system helps geologists to identify physical features of the earth’s surface. The collected data identifies areas with sag ponds, linear scarps or even offset stream beds which indicates a possibility of the fault zone.
5. Model Tsunami inundation: The Washington coastal area is prone to Tsunamis threat. The Lidar system is used to provide an accurate presentation of the ground surface and bathymetry data of the area. The collected data is analyzed and the information is used to predict the exact area where a tsunami is likely to inundate.
This information enables the residents to know the areas they should evacuate in case of emergency.
6. Erosion: Lidar system is used to estimate the eroded volumes of debris slides, gullies, and give detailed information on the altered channels and streams. Mapping the erosional features helps determine the soil erosion volume and depth of the stream.
7. River terrace: Geologists use Lidar technology to identify river terraces, glacial outwash channels, ice sheets, and drumlines features.
8. Floodplains: Lidar system is appropriate for mapping and visualizing geomorphic features of river valleys. It can be used to map areas that are at high risk of floods. Looks at abandoned channels, terraces, ditches and even some sleeves along the floodplains. This information is suitable for managing flood zones, preserve natural features of floodplains and come up with responsive strategies in case floods occur in an area.
9. Structural and bedrock features: Lidar enables geologists to understand the structural and bedrock features like folds, faults, and bedding which are otherwise unavailable or visible in the topographic maps. It provides accurate details to map the various geologic rock units. It determines the depth of the bedrock
10. Weather: Lidar sensors are used to capture weather patterns and impact on the slope stability. The detailed data help determine rock formations and mining excavations in an area.