Greenland tsunami shook earth for nine days | BBC News

Summary

Researchers have identified the cause of a mysterious seismic signal that lasted for nine days in September last year. The signal originated from a massive landslide in a remote fjord in Greenland, which triggered a tsunami. The risk of such Arctic landslides is escalating due to climate change, as glaciers melt and thin, causing mountains to collapse into the water. This event, which saw a mountain's peak disappear into the fjord, was felt globally and serves as a stark reminder of the destructive impacts of climate change.

Takeaways

• 🌏 Researchers have determined the cause of a mysterious seismic signal that shook the Earth for nine days in September last year.
• 🗻 The seismic event was traced back to a massive landslide in a remote fjord in Greenland, which triggered a tsunami.
• 🔍 Scientists analyzed the depth and shape of the 200 km long fjord to understand why the tsunami's effects were felt globally for an extended period.
• 🌊 The wave from the landslide was trapped in the fjord, causing it to bounce back and forth, which led to the prolonged seismic signal.
• 🚢 The area, though remote, is visited by cruise ships; however, no vessels were present during the landslide.
• ❄️ The risk of such Arctic landslides is on the rise due to climate change, according to scientific consensus.
• 🏔️ The glacier that was supporting the mountain had melted and thinned over decades, leading to the catastrophic collapse of millions of cubic meters of rock.
• 🌍 The event highlights the destructive side effects of climate change that can have global impacts.
• 📸 Before and after images of the mountain show the significant change in the landscape caused by the landslide.
• 🌐 The seismic signal was detected by monitors around the world, demonstrating the far-reaching effects of such a localized event.

Q & A

What was the mystery that researchers solved regarding the seismic signal in September?

Researchers solved the mystery of the origins of the seismic signal that shook the Earth for nine days in September, which was caused by a massive landslide in a remote fjord in Greenland.

What was the direct result of the landslide in Greenland?

The direct result of the landslide was a tsunami in the east of Greenland, which was reported by a team working in the area.

How did the seismic signal travel and why was it detected globally?

The seismic signal traveled around the world due to the vibrations caused by the landslide and subsequent tsunami. Seismic monitors around the globe picked up these vibrations.

What was unique about the duration of the seismic signal?

The unique aspect was the long duration of the signal, which lasted for nine days, a scale of movement that had not been previously observed.

Why did the tsunami caused by the landslide last for such an extended period?

The tsunami lasted for an extended period because the wave was essentially trapped in the narrow 200 km long fjord, causing the energy to bounce back and forth without escaping.

What changes in the landscape were observed after the landslide?

The landscape changed significantly as the top of the mountain collapsed into the fjord, taking parts of the glacier with it, as evidenced by before and after images.

Were there any human activities in the area when the landslide occurred?

Although the area is remote, it is visited by cruise ships. Fortunately, no vessels were in the area when the landslide happened.

How is climate change linked to the increasing risk of Arctic landslides?

Climate change is linked to the increasing risk of Arctic landslides because the melting and thinning of glaciers can cause the land they support to become unstable and eventually collapse.

What was the scale of the landslide that caused the seismic signal?

The landslide was massive, involving millions of cubic meters of rock collapsing into the fjord.

What is the significance of this event in terms of understanding the impact of climate change?

This event signifies a destructive side effect of climate change, demonstrating how melting glaciers can lead to significant geological events that can be felt globally.

How did the scientists analyze the depth and shape of the fjord to understand the tsunami's impact?

Scientists analyzed the depth and shape of the narrow fjord to understand why the tsunami's energy was trapped and why it reverberated for an extended period.