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Posts Tagged ‘landslide’

More Countries Harvest Rainwater

Posted in Uncategorized, tagged , , , , , , , on June 16, 2026| 4 Comments »

Photo: Suzanne Bearne.
Above, Nancy Elena Quiros Correa, who says the climate in Medellín, Colombia, has become hotter and wetter. Many neighbors collect containers to store rainwater for washing clothes and flushing toilets.

Remember my recent post about storing rainwater in garden fences (here)? Well, ingenuity is not limited to the Netherlands. People around the world are realizing that climate change calls for storing water. In Medellín, Colombia, violent gangs are no longer getting all the attention, and residents are free to work on the normal challenges of life.

Suzanne Bearne explains at the Guardian.

“In his home on a steep hillside in the neighbourhood of Golondrinas in Medellín, Róbinson Velásquez Cartagena stands proudly next to two large tanks of water – a rainwater harvesting system he designed and built to help reduce the risk of flooding and landslides.

“It is one of the nature-based solutions that Velásquez and others in the community have proposed as part of a disaster risk and climate crisis adaptation plan for Comuna 8, a growing informal settlement of 150,000 people in Colombia’s second-largest city. …

“Neighborhoods such as this, where brick houses with corrugated metal roofs are densely stacked on unstable ground, are susceptible to landslides and floods. In 1987, a devastating landslide killed 500 people in the area.

“Organizations and residents such as Velásquez Cartagena came together and, in 2020, began to develop the Local Agreement for Inclusive Climate Action, in line with the Medellín city council’s Climate Action Plan. …

“The plan was formally launched in August 2023 by several organizations, including Medellín’s disaster risk management department (DAGRD), the housing and habitat committee for Comuna 8, and Heriot-Watt University in the UK. …

“The plan comprises eight measures to address climate risks, including managing rainwater, reforestation to control erosion and sedimentation on hillsides and in ravines, and establishing eco-gardens and agroforestry systems. While the city aims to implement similar plans across all 21 comunas, challenges remain in securing government support and funding for grassroots initiatives.

” ‘I started the rainwater harvesting system because I wanted to prove that it can reduce the risk of disasters by reducing the water that runs on to the streets, which can flood when it rains,’ says Velásquez Cartagena, a community leader. … His system collects water from the rooftop drainage and stores it in containers; he then uses the water for his washing machine and toilet.

“Originally a disaster-management scheme, the plan was expanded by the community to [outline] climate risks and vulnerabilities, a heat map, past floods and landslides, responsible stakeholders and action points.

“ ‘In the plan, there are nature-based solutions, with several that are not that expensive or hard to make,’ says Velásquez Cartagena. …

“In the El Pacifico neighbourhood, Nancy Elena Quiros Correa oversees a small 9 metre by 3 metre (30ft by 10ft) plot that was set up as a community tree nursery last year.

“ ‘The nursery will prevent rocks from falling, soak up water when it rains, and increase biodiversity,’ she says. …

“Other projects include a rainwater-harvesting system installed at a local community center last year and an ecological restoration garden.

” ‘The garden will restore nature and stabilize the land,’ says Harry Smith, a professor in global urbanism at Heriot-Watt University, who has worked with Comuna 8 on environmental projects for the past 10 years. ‘But it also stops one of the problems they have there, which is land invasion as people continue to build new homes on land that has been sold illegally by armed groups.’

“While the plan was being approved, the community ‘hit the ground running,’ says Smith. ‘They wanted to do some pilot projects to show that they don’t need to wait for the municipality to come along and do things.’

“Velásquez Cartagena is working with community leaders to produce a user-friendly guide to the plan, with engaging graphics, that can be printed and shared on social media. …

“Juan David Moreno, the head of the technical team at DAGRD, says: ‘The work in Comuna 8 was a pilot, and we developed it for the rest of the communities. … In some communities, you have different needs,’ says Moreno. ‘We assessed the terrain, the community needs and the different hazards. … The main lesson from Comuna 8 was that we needed to work closely with the people, as they live in the territories and know the local hazards.’ …

“Despite all of their work, Quiros Correa still has reservations about what the plan will achieve. ‘I now have a more realistic view of the local government actions. Everything that we have achieved here has involved fighting and negotiating with the local government.’ ”

More at the Guardian, here. What is your community doing? In our town, anyone who builds hard surface like a macadam parking lot is now responsible for controlling water runoff.

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Rare Books Rescued on Cliff Edge

Posted in Uncategorized, tagged , , , , , , , , , , on June 13, 2026| 4 Comments »

Photo: Sicilian Unit of Firefighters.
Firefighters recovered 350 volumes from a library on the edge of a cliff after a January landslide in Sicily tore away an entire slope of town and carved a chasm.

I wonder if firefighters are taught “Don’t look down.” Being a little acrophobic myself, I can hardly imagine how the book rescuers in today’s story kept from getting dizzy. People I know get dizzy just looking at their feet.

Lorenzo Tondo wrote at the Guardian about the mission.

“Firefighters in Sicily have rescued about 400 rare books from a library in Niscemi that hangs on the edge of a mudflow,” Tondo said, “after a devastating landslide in January tore away an entire slope of the town and carved a [2-mile] chasm.

“The library stands on the lip of the precipice gouged out by the landslide, with part of the building in effect hanging in mid-air. The recovery operation … was preceded by a detailed study of floor plans and interior photographs to map the position of the books.

“Firefighters drilled through the wall of a building behind the structure and, entering for minutes at a time, strapped the bookcases together and hauled them backwards to reach the books.

“The library holds about 4,000 books of literature, history and general nonfiction, including a number of rare editions dating from before 1830 on Sicilian history. Among its most precious treasures is a 16th-century book.

“ ‘It was like pulling off a bank heist,’ said Salvatore Cantale, the provincial commander of the fire brigade in Caltanissetta. ‘We had to be quick and try to take away as much as we could.’

“A drone streamed live aerial images to a monitor on the ground, while laser sensors fixed to the section teetering over the drop were used to detect the slightest movement. A separate device monitored vibrations and subtle shifts in the building’s tilt.

“The landslide began on 25 January when the ground started to shift, cracking asphalt and tearing through buildings. Some later collapsed into the void, along with a stretch of road where cars and vans had been parked. More than 1,600 people have been evacuated from the town.

“Many of the volumes remain in the basement, which is considered the most at-risk area. Officials are weighing up the use of robots, though none suitable are available in Niscemi. … Cantale said, ‘The problem is that this building is effectively a single reinforced-concrete structure. If it collapses, it will go all at once.’

“Cantale said the geologists working next to the firefighters expected the landslide’s front to retreat by another 10 to 15 metres, dragging further buildings down the slope with it, including the library.

“He said: ‘According to the geologists, rather than crumbling, the library is more likely to slide downhill as a single block. If that happens, we have already assessed that it may actually be easier to recover the remaining books once it has fallen.’ “

More at the Guardian, here.

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Weird Seismic Rumble

Posted in Uncategorized, tagged , , , , , , , on November 21, 2024| Leave a Comment »

Photo: Soren Ryesgaard.
A boat looks tiny cruising by the rockslide gully of a destroyed glacier in Greenland recently. Rockslide plus global warming equals a surprise.

I don’t remember reading about this mysterious rumble at the time, but I’m always interested when scientists are stumped. I like how they approach figuring out a new phenomenon. Here’s hoping that science will continue to guide us the future. For one thing, unlike business or politics, it is usually collaborative, as seen in this story.

Kasha Patel wrote at the Washington Post, “The strange rumble was detected mid-September last year. An odd seismic signal appeared at scientific stations around the globe, but it didn’t look like the busy squiggles of an earthquake. A day passed, and the slow tremor still reverberated. When it continued for a third day, scientists worldwide began assembling to discuss what was causing the grumble in the ground.

“Some initially thought the seismic instruments recording the signal were broken, but that was quickly nixed. Maybe it was a new volcano emerging before their eyes, others said. …

“ ‘No one had ever seen this. We have nothing to compare it with,’ said Kristian Svennevig, a geologist at the Geological Survey of Denmark and Greenland.

“Nine days later, the vibrations greatly dissipated. But the mystery of the USO [Unidentified Seismic Object] lasted much longer. A year later, the puzzle has been solved, according to a study published in the journal Science [in September 2024]. It took about 70 people from 15 different countries and more than 8,000 exchanged messages (long enough for a 900-page detective novel) to crack the case.

“The short answer: A mega-tsunami created waves that sloshed back and forth in a fjord in Greenland, creating vibrations that traveled around the world.

“The long answer begins in the atmosphere. As greenhouse gas concentrations increase due to climate change, those heat-trapping gases accelerate ice melt particularly around Earth’s poles. On Sept. 16 last year, that extra heat thinned a glacier in eastern Greenland over time so much that it could no longer support the mountain rock above it.

“A 500-foot-thick piece of metamorphic rock, about a third of a mile wide and long, fell and triggered a massive landslide. Rock and ice, enough to fill 10,000 Olympic-size swimming pools, let loose as fast as 47 meters per second and ran for more than a mile. The avalanche plunged into the Dickson Fjord, triggering a 650-foot-high tsunami — one of the highest seen in recent history.

“Farther away from the fjord, tsunami waves reaching 13 feet high damaged an unoccupied research station and destroyed cultural and archaeological heritage sites, including an old trapper hut that had never been affected by tsunamis during its century-old history. …

“Meanwhile, in the fjord, the mega-tsunami wave traveled back and forth in the inlet and created a standing wave called a seiche. We often see small-scale seiches — this rhythmic oscillation in water — in a swimming pool or bathtub. This tsunami source was so energetic that the seiche radiated seismic waves globally, shaking the planet for nine days before it petered out.

“Members of the Danish military sailed into the fjord only days after the event to collect drone imagery of the collapsed mountain face and glacier front and scars left by the tsunami.

“Of course, Svennevig and many of his close colleagues didn’t fully know of the connection between the tsunamigenic landslide and the seiche as the events unfolded, which is detailed in the study.

“At the time, they were scratching their heads about the data at the seismograph stations. The seiche appeared as a single slow vibration, like a monotonous-sounding hum, as opposed to the frantic lines of a typical earthquake reading. The wave peaked every 92 seconds, which is slow compared with an earthquake. …

“ ‘When we started doing this research, nobody had any ideas about what was the root cause,’ said Carl Ebeling, a co-author of the study and a seismologist at the Scripps Institution of Oceanography at the University of California at San Diego. ‘Even for a large landslide under normal circumstances, it would be hard to see that on a global scale, so something special is going on here.’

“As some scientists investigated the peculiar seismic data, another group of authorities and researchers had heard of a large tsunami in a remote fjord in eastern Greenland. The two teams, among others, joined forces, quickly growing into a 24/7 international collaboration via a messaging system. The group brought a variety of local field data and remote, global-scale observations.

“ ‘We knew there was a landslide and a tsunami. You could pull the seismic signal of those,’ Svennevig said. ‘But then there was this other seismic signal that continued for nine days, and they were taken from roughly the same area, so they must be associated somehow.’ …

“The breakthrough came when they received new bathymetry data of the fjord, similar to a topographic map, from the Danish military, which allowed them to better map the seabed in the computer models. Once incorporated, the team used an unprecedentedly high resolution model to show how the landslide direction, along with the uniquely narrow and bendy fjord channel, led to the nine-day seiche.”

More at the Post, here.

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