The study investigates how human land use can increase tsunami danger in lakes by sending extra sediment into steep, unstable deltas. In northern Italy’s Lake Iseo, deforestation, farming and pastoralism since Roman times tripled sediment delivery to the Oglio River Delta, building and oversteepening its underwater slopes. Geological records show that earthquakes in 1117 and 1222 triggered major collapses there. The first mobilized about 62 million cubic metres of sediment; the second, about 10 million. Sediment cores and seismic surveys identify the resulting deposits, while numerical simulations reconstruct the failures and their waves. Historical accounts and archaeological evidence support the reconstructions.
The modeled tsunamis reached maximum run-ups of roughly 50 metres in 1117 and 13 metres in 1222. After the first collapse, continued sediment input rapidly rebuilt the delta, helping set up another failure about a century later. Eight centuries of further erosion-driven accumulation have again left shoreline communities exposed to earthquake-triggered collapse. A global synthesis indicates that human-driven erosion has risen to its highest levels since the Industrial Era, adding sediment to lake deltas worldwide. The findings show that human activity can amplify both the likelihood and severity of lake tsunamis, and that hazard assessments should account for changing sediment supply as well as earthquakes.
Summary generated by AI from the linked article. hn.today is not affiliated with Hacker News or Y Combinator.
The developing human brain loses many neurons with chromosome abnormalities around birth: over 25% of sampled fetal neurons had major genetic changes, compared with about 6% of neurons from babies after birth. Researchers say this process may help the brain select healthy neurons and could shed light on childhood conditions such as autism and epilepsy. (nature.com)
The EU plans to require member states to prepare for a 3°C rise in global temperatures, including assigning agencies to manage climate risks. The proposal shifts focus toward adaptation as emissions cuts fall short, with the Commission estimating Europe needs €70 billion annually for climate resilience through 2050. (ft.com)
The Ez-PAVE trial found that targeting LDL below 55 mg/dL reduced cardiovascular events over three years to 6.6%, compared with 9.7% for a target below 70 mg/dL. The benefit came mainly from fewer heart attacks and procedures; the trial did not establish a reduction in cardiovascular deaths. (empirical.health)
U.S. colorectal cancer incidence rose in 2023 after declining for more than two decades, with increases across age groups through 69. The sharpest rise was among adults aged 45-49, highlighting growing needs for screening, treatment, and survivorship care. (uchicagomedicine.org)
The Vera C. Rubin Observatory discovered 2026 ED138, a Kuiper Belt object estimated to be 600-1,500 kilometers wide and a potential dwarf planet. Its orbit stays within Pluto’s range from the Sun, yet it went undetected until now. (sciencealert.com)
Spider silk starts as a liquid protein mixture that rapidly transforms into a strong, flexible fiber tougher than Kevlar. Researchers are probing the molecular changes behind this spinning process to help create high-performance synthetic materials. (quantamagazine.org)
Today's best Hacker News stories, summarized and screenshotted, one email a day.