An earthquake of 8.8 magnitude, one of the 10 strongest ever recorded, struck Russia’s Far East early on Wednesday, leading to a tsunami alert throughout the Pacific region.
Even as “tsunami waves” were reported in Japan and Alaska, panic spread through Japan to the US state of Hawaii. Governments moved to evacuate coastal cities facing a greater risk of potentially massive waves crashing into urban areas.
Despite giant scientific leaps that have enabled the human race to forecast major climatic and natural disasters, including tsunamis, earthquakes remain largely unpredictable. There is no accurate warning system for earthquakes, and any progress towards building one is hardly substantive.
Experts say earthquake prediction is “extremely hard” because of the complexity of fault lines, points where massive and irregularly shaped slabs of solid rock called tectonic plates meet below the Earth’s surface.
These plates are in constant motion, albeit at a glacial pace of a few centimetres a year. The movement of these tectonic plates is driven by the currents in the mantle, a layer inside the Earth bounded below by a core and above by a crust.
“Trying to pick out what is a clear signal of a precursor to a potentially catastrophic shift versus the normal background noise of the Earth’s movement is difficult,” says Kit Yates, a senior lecturer in mathematical biology at the University of Bath in the UK.
Distinguishing actual signals of seismic activity from human activities, such as construction work, heavy traffic and even music concerts, is a near impossibility. 
For example, US singer Taylor Swift performed in July 2023 at a stadium filled with 72,000 people, causing a seismic activity equivalent to a 2.3-magnitude earthquake.
Seismologists say earthquakes do not always have consistent warning signs or precursors. In other words, a geological research body can collect seismic activity data as diligently as possible for years on end, and still miss a massive earthquake simply because of the absence of any warning sign.
The science behind earthquakes
The boundaries where the tectonic plates interact are the primary zones where earthquakes occur. There are three main types of plate boundaries: divergent, convergent, and transform.
At divergent boundaries, plates move apart, creating a new crust. Convergent boundaries involve plates colliding, with one often being forced beneath another. 
Transform boundaries – where plates slide past each other horizontally – are the ones that generate earthquakes.
Earthquakes happen when the stress accumulated along these plate boundaries exceeds the strength of the rocks, causing them to fracture and release energy in the form of seismic waves. 
If the seismic activity is under the bed of an ocean near a populated piece of land, it creates a tsunami with massive waves ravaging the coastal belt.
The magnitude of an earthquake, measured on the Richter scale, reflects the energy released. The intensity of an earthquake is felt on the surface, and depends on factors like depth, distance from the epicentre.
The energy released during an earthquake varies. Small earthquakes, which occur frequently, release minor amounts of energy and often go unnoticed. Major earthquakes, however, can release energy equivalent to thousands of atomic bombs, causing catastrophic damage.
Technological advances, such as machine learning and real-time monitoring, have improved the seismologists’ ability to detect patterns and issue rapid warnings, but only after an earthquake begins. 
Earthquake early warning systems, like those in Japan and California, use initial seismic waves to alert people seconds to minutes before shaking reaches them. These systems detect quakes already in progress, not predict them before they start.
Another major barrier to precise predictions is the rarity of large earthquakes. Major earthquakes are infrequent, which makes the data needed to understand their precursors insufficient.
 
Experts say governments should adopt mitigation measures in the absence of reliable earthquake prediction systems. These measures include stronger building codes, retrofitting infrastructure, and public education.
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Source: TRT