19/06/2026 19:06 - Tecnologia
Visualización artística del interior de la Tierra con ondas sísmicas viajando desde Japón hacia el núcleo externo y rebotando de vuelta. Capas terrestres en diferentes colores (corteza marrón, manto naranja, núcleo externo amarillo brillante). Flechas curvas mostrando el recorrido de la onda. Estilo científico-educativo moderno y limpio.
On Friday, March 11, 2011, at 2:46 PM local time, a massive magnitude 9.1 earthquake struck off the coast of Honshu, Japan's main island. This seismic event —known as the Great East Japan Earthquake and Tsunami— became the strongest earthquake ever recorded in Japanese history and the third most powerful worldwide since 1900. The epicenter was located in the Pacific Ocean, approximately 130 kilometers (80 miles) east of Sendai, a major city in the Tōhoku region.
The resulting tsunami, with waves reaching staggering heights of up to 40 meters (130 feet), devastated coastal communities and triggered the infamous Fukushima nuclear disaster. The tragedy claimed nearly 20,000 lives and remains one of the deadliest natural disasters in modern history.
For over a decade, scientists believed they understood the full scope of the 2011 disaster. But new research published in the prestigious journal Science has revealed an astonishing phenomenon: approximately 15 minutes after the main earthquake, GPS stations across Japan detected that the entire archipelago had shifted uniformly eastward by 5 to 6 millimeters.
The research was led by geophysicist Sunyoung Park from the University of Chicago, in collaboration with renowned seismologists Hiroo Kanamori (Caltech) and Luis Rivera (University of Strasbourg). Their findings reveal a mechanism never before documented:
The earthquake generated a powerful shear wave (known as the ScS phase) that traveled deep into the Earth's interior, descending toward the planet's core.
When the wave reached the Earth's outer core —a liquid layer of metallic alloy located about 2,900 km (1,800 miles) deep— it reflected completely and began its journey back to the surface.
Traditional seismic sensors are designed to detect high-frequency signals from nearby earthquakes. This newly discovered phenomenon involves low-frequency waves that travel enormous distances through the planet's interior. The total round-trip journey covered approximately 5,800 kilometers (3,600 miles).
Simplified explanation: Shear waves (S-waves) cannot travel through liquids. When these waves encounter the liquid outer core, they cannot pass through it, so they reflect back toward the surface like a ball bouncing off a wall.
Japan sits in one of the most geologically active zones on Earth. The country is located at the intersection of four major tectonic plates: the Pacific Plate, the Philippine Sea Plate, the Eurasian Plate, and the Okhotsk Plate. This configuration, called a "double subduction zone," means multiple plates are simultaneously diving beneath each other, creating enormous stress that periodically releases as earthquakes.
The researchers determined that this phenomenon affected an area spanning approximately 3,000 kilometers (1,860 miles) —making it the largest lateral seismic event ever documented. For context, this is 6 to 7 times larger than the original earthquake's rupture length.
| Measurement | Value |
|---|---|
| Country's displacement | 5-6 mm eastward |
| Time delay after main quake | 13-16 minutes |
| Wave travel distance | ~5,800 km (round trip) |
| Affected area | ~3,000 km |
| Earthquake magnitude | 9.1 |
| Casualties | Nearly 20,000 |
| Tsunami maximum height | 40 meters (130 feet) |
This discovery fundamentally changes how scientists understand earthquake hazards. Sunyoung Park emphasized: "This indicates that large earthquakes can influence fault zones even after the main shaking has ended. This adds a completely new dimension to seismic hazard assessment that we weren't aware of before."
The Tōhoku earthquake was so powerful that it had measurable effects on the entire planet:
What makes this finding so significant is that it reveals earthquakes don't simply "end" when the shaking stops. The energy released continues to interact with the planet's interior, traveling thousands of kilometers before returning to the surface with measurable consequences. For a country like Japan, which experiences roughly 1,500 earthquakes annually (though most are minor), understanding these complex dynamics is crucial for public safety.
Alfredo S. Quiroga
