Phys.org June 13, 2022 The colossal eruption of the Hunga Tonga-Hunga Ha’apai volcano and ensuing tsunami is the first global volcano-triggered tsunami recorded by modern, worldwide dense instrumentation, thus providing a unique opportunity to investigate the role of air-water coupling processes in tsunami generation and propagation. An international team of researcher (Portugal, UK, USA – Columbia University, Spain) used sea-level, atmospheric and satellite data from across the globe, along with numerical and analytical models, to demonstrate that this tsunami was driven by a constantly moving source in which the acoustic-gravity waves radiating from the eruption excite the ocean and transfer […]
Tag Archives: Natural disaster
New method for detecting pre-eruption warning signals at Whakaari White Island and other active volcanoes
Phys.org April 20, 2022 Even with real-time geophysical monitoring, forecasting sudden eruptions is difficult, because their precursors are hard to recognize and can vary between volcanoes. An international team of researchers (New Zealand, Belgium) has described a general seismic precursor signal for gas-driven eruptions, identified through correlation analysis of 18 well-recorded eruptions in New Zealand, Alaska, and Kamchatka. The precursor manifested in the displacement seismic amplitude ratio between medium (4.5–8 Hz) and high (8–16 Hz) frequency tremor bands, exhibited a characteristic rise in the days prior to eruptions. They interpreted this as formation of a hydrothermal seal that enables rapid pressurization of […]
Tonga Islands: A seismic algorithm reveals the magnitude of the January 2022 eruption
Phys.org April 20, 2022 By analyzing the seismic waves researchers in France were able to design an algorithm that can detect and locate a volcanic eruption in near real-time and, using equations that describe explosive eruptions, assess its size. Until now, such an assessment required field work and took several weeks or months, since it was necessary to estimate the volume of ash and lava produced. The authors show that the Hunga Tonga eruption ejected a volume of around 10 km3, making it the largest explosive eruption of the twenty-first century, equivalent in strength to that of the devastating eruption […]
Tongan volcano eruption leaves scientists with unanswered questions [24 minutes]
Nature Podcast February 16, 2022 On the 15th of January, a volcano in the South Pacific Ocean erupted, sending ash into the upper atmosphere, and unleashing a devastating tsunami that destroyed homes on Tonga’s nearby islands. Now scientists are trying to work out exactly what happened during the eruption — and what it means for future volcanic risks. Podcast
Machine learning refines earthquake detection capabilities
Science Daily November 1, 2021 New satellites are opening a new window into tectonic processes by allowing researchers to observe length and time scales that were not possible in the past. However, existing algorithms are not suited for the vast amount of InSAR data flowing in from these new satellites. To process all this data an international team of researchers (USA – Los Alamos National Laboratory, France) developed the first tool based on machine learning algorithms to extract ground deformation from InSAR data, which enables the detection of ground deformation automatically — without human intervention — at a global scale, […]
Leading scientists warn of global impacts as Antarctic nears tipping points
Phys.org June 16, 2021 According to a panel of leading Antarctic scientists human-driven climate change is pushing the Antarctic towards numerous tipping points that will impact wider earth systems, with profound implications for humanity and biodiversity. They examine how climate change is rapidly pushing five critical, interconnected processes in the Antarctic Southern Ocean towards substantial changes. They warn that disrupting these processes may disproportionately exacerbate global climate change and have widespread impacts on marine and human life worldwide, due to the region’s central role in regulating our earth systems. According to the group we can build resilience in the Antarctic […]
Response to fire impacts water levels 40 years into future
Science Daily January 10, 2020 Few studies have investigated the longer‐term effects of either wildfire or post‐fire land management on catchment hydrology. A team of researchers in the US (UC Santa Barbara, Oregon State University, industry) analyzed ten years of pre‐fire data, along with post‐fire data from 1 to 7 and 35 to 41 years after wildfire burned three experimental catchments in the Entiat Experimental Forest (EEF) in the Pacific Northwest. They quantified and compared the short‐ and longer‐term effects of both wildfire and post‐fire forest management treatments on annual discharge, peak flows, low flows, and evapotranspiration (AET). They found increases […]
Fukushima: Lessons learned from an extraordinary case of soil decontamination
Science Daily December 12, 2019 After the Japanese authorities completed decontaminating of most of the affected area an international team of researchers (France, Canada, Japan) provided an overview of the decontamination strategies used and their effectiveness from approximately sixty scientific publications, with a focus on radiocesium. Radioactive cesium has a half-life of 30 years, it constitutes the highest risk to the local population in the medium and long term, as it can be estimated that in the absence of decontamination it will remain in the environment for around three centuries. In cultivated areas within the special decontamination zone, residential areas […]
Scientists call for microbial ‘Noah’s Ark’ to protect global health
Science Daily October 4, 2018 A team of researchers in the US (Rutgers University, UC San Diego, University of Chicago, New York University) is calling for the creation of a global microbiota vault to protect the long-term health of humanity similar to the Svalbard Global Seed Vault, the world’s largest collection of crop diversity created in case of natural or human-made disasters. According to the researchers over a handful of generations, we have seen a staggering loss in microbial diversity linked with a worldwide spike in immune and other disorders. It may be possible one day to prevent disease by […]
Research finds quakes can systematically trigger other ones on opposite side of Earth
Oregon State University August 1, 2018 Researchers at Oregon State University analyzed seismic data from 1973 through 2016, excluding data from aftershock zones, using larger time windows than in previous studies. A tremblor is most likely to induce another quake within 30 degrees of the original quake’s antipode – the point directly opposite it on the other side of the globe. The understanding of the mechanics of how one earthquake could initiate another while being widely separated in distance and time is still largely speculative. But irrespective of the specific mechanics involved, evidence shows that triggering does take place, followed […]