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| Science & Technology |
| You can't hear it, but this sound can reveal that a tornado is on its way |
| 2024-03-16 |
| [BBC] The terrifying, destructive power of tornadoes is as sudden as it is violent. Now scientists are eavesdropping on twisters to develop new early warning systems and fight warning fatigue. It begins with the rustling of leaves, sinister squeak of hinges and the creak of nearby trees. Then comes a deafening rumble like an approaching freight train, the terrifying screech of nails being ripped from wooden boards and unpredictable thuds from flying debris. These are the sounds often described by tornado survivors recounting their escape from these storms. They rarely have much warning, but it is often enough to save lives. There's another sound, however, that accompanies tornadoes that we can't hear. It is so low in frequency it is beyond the realms of human hearing, but it could offer a way of providing earlier, more accurate warnings of these destructive storms. With winds that can reach up to 483km/h (300mph), the storms that produce tornadoes generate low frequency sound waves – or infrasound – that can travel for hundreds of miles. Eavesdropping on these infrasound signals may not be able to prevent tornadoes from flattening towns and tossing cars into the air like toys, but it could lead to a new type of early warning system that might save lives. SHAKY PREDICTIONS Around 1,200 tornadoes leave trails of destruction in the US in an average year, with most occurring on the Great Plains of the central US. (Read about how tornado alley is changing.) They cause millions, and in some years, billions of dollars-worth of damage annually and claim an average of 87 lives a year since 1951 (although the number of fatalities varies wildly from year to year). According to the National Oceanic and Atmospheric Administration (Noaa), 76 people have died in around 1400 tornadoes in the US in 2023 so far. At least 26 people were killed in Mississippi when a unusually long-lived tornado damaged more than 2,000 homes along a 59 mile (94km) path. In December 2023, two people were killed – a mother and her two year old son – when several powerful tornadoes tore across Tennessee. Powerful storms that, included reports of tornadoes, swept through eastern Indiana and western Ohio on 14 March, leaving at least three people dead. Yet twisters are notoriously difficult to forecast because we still don't have a clear picture of why they do and do not form. Even when they do form, the violent column of air behaves erratically. |
| Posted by:Skidmark |
| #4 BBC discovers the 1990's. |
| Posted by: swksvolFF 2024-03-16 10:09 |
| #3 Our dog seems to be able to detect thunder miles beyond our hearing. Our Pyrenees girl would travel that distance to confirm. |
| Posted by: Mullah Richard 2024-03-16 09:45 |
| #2 Our dog seems to be able to detect thunder miles beyond our hearing. |
| Posted by: Bobby 2024-03-16 09:16 |
| #1 It sounds like a voice in the distance crying "Dorothy! Dorothy!". |
| Posted by: SteveS 2024-03-16 08:56 |