Tsunami-proofing the future: Seven smart solutions to shape safer shores
With ever-expanding coastal communities comes increased numbers of people exposed to the risk of tsunamis. However, disaster risk reduction innovators are devising smart solutions to bolster disaster preparedness and build resilience.
These seven cutting-edge solutions exemplify how clever design can protect coastal communities and help prevent tsunamis from becoming disasters.
1. A self-raising barrier against tsunami threats
Tokyo Institute of Technology researchers have developed a dynamic seawall system (SMS) that uses microtidal energy to generate its own power to raise gates from the seafloor, protecting Japan's ports from tsunamis, storm surges, and high waves. This self-powered barrier system enhances disaster resilience by securing vital coastal infrastructures, and, as a bonus benefit, generates surplus electricity for emergency use during power outages-a critical multiplier of disaster risk. Successfully tested in several Japanese ports, particularly along the tsunami-prone Nankai Trough, SMS offers a sustainable and robust disaster prevention solution, with the potential for potentially more widespread adoption as a pioneering technology in tsunami protection.
2. GPS-based tsunami warnings offer faster, global protection
A novel tsunami detection method uses existing GPS satellites, which could provide quicker and more accurate warnings globally. This method, developed by researchers from the University College London (UCL) and universities in Japan, detects tsunamis by analysing changes in Earth's ionosphere, about 300 km above ground, where initial tsunami waves cause a reduction in electron density, affecting GPS signals. In studying data from the 2011 Tohoku-Oki tsunami, researchers found that a warning could have been issued within 15 minutes of the earthquake, giving critical time for evacuation. Unlike traditional systems, this approach doesn't rely solely on earthquake data, making it useful for tsunamis from landslides or volcanic eruptions. As a relatively low-cost method, it could improve current warning systems, especially in regions with limited GPS networks, offering more accurate predictions and timely alerts.
3. Tonga's tsunami resilience upgrade
Tonga has made strides in strengthening its disaster preparedness, with initiatives like the Weather Ready Pacific Program and new legislation on disaster management, following the devastating Hunga Tonga-Hunga Ha'apai eruption and resulting tsunami of 2022. This eruption was the largest volcanic event of this century, producing 20-meter waves that wreaked havoc on the island's infrastructure and economy. However, thanks to early warnings, local knowledge, and a vigorous public awareness campaign, many lives were saved through the quick evacuation of residents to safe locations. The resilience of Tonga's community shows how technology, awareness and support can make a difference for Small Island Developing States in the Pacific.
4. Harnessing nature's power for tsunami protection
A groundbreaking dataset measuring wave height attenuation by mangrove trees demonstrates the potential of these coastal forests as a natural solution to tsunami protection. This study, published in Frontiers in Marine Science and winner of the 2022 DesignSafe Dataset Award, quantifies how mangroves effectively reduce wave energy, acting as a crucial barrier against tsunami and hurricane damage. Researchers constructed a prototype-scale model of an artificial mangrove forest in an Oregan State University wave tank, demonstrating the significant wave attenuation achieved by the dense thicket of mangrove roots. By gathering data on the engineering performance of mangroves, this research integrates natural systems into disaster resilience strategies, providing an eco-friendly approach to safeguarding coastal communities from the devastating impacts of tsunamis and rising sea levels.
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5. AI boosts acoustic technology for faster tsunami warnings
An innovative early warning system combines advanced acoustic technology with machine learning to assess tsunami risks triggered by underwater earthquakes. Recognizing that the type of earthquake -specifically whether it involves vertical or horizontal movement- plays a critical role in determining tsunami potential, the research team from UCLA and Cardiff University uses hydrophones to capture acoustic radiation produced by seismic events. This sound travels much faster than tsunami waves, allowing for quicker analysis and classification of the earthquake's characteristics in real time. By triangulating the earthquake's source and employing AI algorithms to evaluate its parameters, the system can provide earlier timely alerts to mitigate the dangers posed by tsunamis, thus enhancing existing hazard warning systems and improving safety for coastal communities and maritime operators.
6. Unveiling early signals in Earth's magnetic field
Early signals of an impending tsunami may be hidden within Earth's magnetic field, offering a potential breakthrough for tsunami warning systems. Following the devastating 2009 tsunami that struck American Samoa, researchers led by Zhiheng Lin from Kyoto University explored how tsunami-generated magnetic fields could provide early warnings. Unlike traditional systems that rely on ocean buoys and can be slow to respond, the magnetic fields generated by ocean movement can be detected more rapidly, potentially giving communities an extra minute or more to prepare. By analyzing data from the 2009 tsunami and another event in 2010, Lin's team demonstrated that magnetic signals arrived at least a minute earlier than sea level changes. In addition to improving tsunami forecasting, this innovation could also enhance understanding of the conditions that lead to such disasters. Establishing a network of permanent magnetometers in ocean basins could complement existing early-warning technologies.
7. Modelling 300,000 years of earthquakes to assess tsunami risks
Certain earthquakes could generate tsunami waves reaching heights of up to 28 meters along the coast of Aotearoa New Zealand. Researchers from Te Herenga Waka Victoria University of Wellington used a physics-based earthquake catalogue, overcoming previous assessment challenges tied to the rarity of tsunamis. By modelling tsunamis produced by 2,585 significant earthquakes from a synthetic earthquake catalogue simulating over 300,000 years of seismic activity, the research highlights that earthquakes from the Hikurangi and Tonga-Kermadec subduction zones present the greatest risks. This method not only enhances understanding of potential tsunami impacts but also paves the way for next-generation risk modelling for various natural hazards in New Zealand.
The magic mix of old AND new
As coastal populations continue to swell, innovative solutions can complement more traditional approaches to safeguard at-risk communities. By combining natural defences -such as mangrove forests - with advanced detection systems, such as GPS and magnetic field analysis; and by completing tried-and-tested community-based awareness and preparedness programmes with earlier, more rapid detection methods, we can empower communities to respond more effectively when tsunamis strike.
As these approaches evolve and gain traction, they add new tools to our toolkit, paving the way for a safer future for coastal regions worldwide. See what else countries can do to prepare.