Earth’s surface is constantly changing as a result of both natural and human processes, and humanity’s exposure to natural hazards is increasing. NISAR will measure these changes, from small movements of the crust up to volcanic eruptions.
Human populations are increasing in high-risk areas vulnerable to sea level change, land subsidence, tsunamis, volcanoes, earthquakes and landslides. These hazards already cause thousands of deaths and billions of dollars in damage every year. Improved forecasting and mitigation necessitate understanding these natural hazards, with measurements throughout the hazard cycle. Many natural disasters deform the land surface subtly before a catastrophic event, and tracking these subtle changes will provide greater insight into hazards such as earthquakes, landslides and volcanic eruptions.
NISAR’s global and rapid coverage will provide unprecedented opportunities for disaster response, providing data to assist in mitigating and assessing damage, with observations before and after disasters in short time frames.
Addressing an Increasing Exposure to Natural Disasters
Society’s exposure to natural hazards is rapidly increasing. Large, dangerous earthquakes are thought to be overdue in densely populated regions of the U.S. West Coast, home to about 50 million citizens. Volcanic eruptions endanger many areas of Earth and often disrupt air travel. Sinkholes are common in areas where easily dissolved rock belowground can threaten buildings and infrastructure. Water is an increasingly scarce resource, and water storage and distribution systems must be safe and resilient for current and increasing needs.
Many hazards such as earthquakes and volcanic unrest subtly change and deform the land surface before they become catastrophes. The best way to properly prepare for, mitigate and respond to nature’s disasters is to detect, measure and understand these slow-moving processes before they either trigger a major disaster or compromise our natural resources. This requires relevant, comprehensive, details, and accessible observations of subtle but detectable motions, collected over time.
Mitigating Disasters and Sustaining Resources
Natural disasters often occur abruptly and without notice. Earthquakes, volcanic eruptions and landslides are sudden events that can cause billions of dollars in damage and extensive loss of life. Subsidence from water, oil or gas withdrawal from the ground and underground dissolution of limestone can have major impacts on agriculture, levees and our built environment.
Forces deep within Earth drive motion of the tectonic plates, causing earthquakes and volcanic eruptions while shaping our landscapes. Withdrawal, injection and movement of fluids at depth also cause small but detectable motions of Earth’s surface.
It is crucial for our society and economy to mitigate losses from disasters. We need informed decisions in order to carry out effective mitigation and make the most of our resources sustainably and economically. By measuring motions and other changes of the Earth’s surface, we can understand processes occurring at depth and disentangle other impacts.
Benefiting Forecasting, Response and Resource Management
Natural hazards will continue to threaten our country. NISAR’s global and rapid coverage will provide unprecedented opportunities to mitigate widespread damage and assess its extent. Detecting surface motions of our planet will help illuminate the processes occurring deep within.
Because NISAR's data will be open access, more policy makers worldwide will be able to use them to meet scientific, societal and commercial goals than can use other data that are not as accessible.
Science-based management and storage of freshwater and energy sources will allow us to use these resources more efficiently and sustainably.
Rapid, Detailed Damage Assessment
Following the February 2011 earthquake in Christchurch, New Zealand, JPL researchers produced a damage map by comparing before and after radar images of Christchurch from the Japanese Advanced Land Observing Satellite (ALOS) satellite. This method detected building damage, liquefaction and a small landslide. The ALOS map compared favorably to official maps, which were produced later. NISAR maps will allow initial damage estimates to guide ground inspections for damage assessment.