Tre milioni di americani, soprattutto in Oklahoma e Kansas, sono a rischio per i terremoti indotti dall'uomo quest'anno. Lo si apprende da un rapporto dell'US Geological Survey, secondo cui a innescarli è lo smaltimento delle acque reflue generate durante l'estrazione di petrolio e gas con il metodo del fracking.
Si tratta comunque di un numero inferiore a quello dello scorso anno, pari a sette milioni. "La buona notizia è che la pericolosità sismica globale per quest'anno è inferiore rispetto al 2016, ma nonostante questo calo c'è ancora una significativa probabilità di danni a causa delle scosse", ha spiegato Mark Petersen, capo dell'USGS National Seismic Hazard Mapping Project.
Gli esperti dell’istituto informano che, utilizzando la tecnica della fratturazione idraulica, le acque di scarico vengono raccolte e, successivamente, smaltite mediante iniezione in pozzi sotterranei ad alta pressione, riempiendo i pori in faglie dormienti e scatenando, infine, i movimenti tellurici.
ATS/AnP
%20--%3e%3csvg%20version='1.1'%20id='Layer_1'%20xmlns='http://www.w3.org/2000/svg'%20xmlns:xlink='http://www.w3.org/1999/xlink'%20x='0px'%20y='0px'%20viewBox='0%200%20138.2%2048'%20style='enable-background:new%200%200%20138.2%2048;'%20xml:space='preserve'%3e%3cstyle%20type='text/css'%3e%20.st0{fill-rule:evenodd;clip-rule:evenodd;fill:%23AF001E;}%20.st1{fill-rule:evenodd;clip-rule:evenodd;fill:%23FFFFFF;}%20%3c/style%3e%3cpath%20class='st0'%20d='M0,48h138V0H0V48z'/%3e%3cpath%20class='st1'%20d='M9.3,31.7l-0.4,2.7C8.8,35,9,35.2,9.5,35.3c2,0.2,4,0.3,6.1,0.3c5.6,0,9.7-1.8,9.7-7.1c0-3.1-1.3-5.4-6-6.6%20l-2.6-0.7c-1.8-0.5-2.6-1-2.6-2.3c0-1.9,1.7-2.2,3.3-2.2c2.2,0,4.4,0.2,5.3,0.2c0.9,0.1,1.2,0,1.3-0.8l0.4-2.6c0-0.1,0-0.2,0-0.3%20c0-0.1-0.1-0.2-0.1-0.3s-0.1-0.1-0.2-0.2c-0.1,0-0.2-0.1-0.3-0.1c-2-0.2-4.1-0.3-6.1-0.3C11.8,12.4,9,14.9,9,19c0,3.6,2,5.8,5.4,6.7%20l2.6,0.7c2.1,0.6,3,1.2,3,2.5c0,2-1.3,2.3-4.6,2.3c-1.5,0-4-0.2-4.9-0.3C9.6,30.9,9.4,31,9.3,31.7'/%3e%3cpath%20class='st1'%20d='M36.4,23.6l-0.3,1.5C36,25.4,36,25.6,36,25.9c0,0.4,0.1,0.8,0.4,1.1l4.2,7.6c0.1,0.3,0.3,0.5,0.6,0.7%20c0.3,0.2,0.6,0.2,0.9,0.2h3.8c0.5,0,1.1-0.3,0.5-1.2l-5.1-8.6c1.7-1.1,3.6-2.6,3.6-6.1c0-4.4-2.5-6.9-7.9-6.9h-7.8%20c-0.7,0-0.9,0.2-0.9,1v20.8c0,0.7,0.2,1,0.9,1h3.2c0.7,0,0.9-0.2,0.9-1V16.8h3.3c2.1,0,3.1,0.8,3.1,2.8c0.1,0.6,0,1.2-0.3,1.6%20c-0.3,0.5-0.7,0.9-1.3,1.1C37.1,22.7,36.8,22.3,36.4,23.6z'/%3e%3cpath%20class='st1'%20d='M66.1,34V22.7c0-0.7-0.2-1-0.9-1h-5.8c-0.7,0-0.9,0.2-0.9,1v2.5c0,0.7,0.2,0.9,0.9,0.9h1.7v5%20c-0.6,0.1-1.1,0.1-1.7,0.1c-4.8,0-6-3.1-6-7.4c0-5.4,2-6.8,6.5-6.8c1.3,0,3.1,0.1,4.1,0.2c1,0.1,1.2,0,1.3-0.8l0.4-2.5%20c0.1-0.7,0-1-0.8-1.1c-1.8-0.2-3.6-0.3-5.4-0.2c-8.2,0-11.6,4.3-11.6,11.3s2.7,11.9,11.3,11.9c2,0.1,4,0,6-0.4%20C65.9,35.2,66.2,34.9,66.1,34'/%3e%3cpath%20class='st1'%20d='M74.9,31.7l-0.4,2.7c-0.1,0.5,0.2,0.7,0.6,0.8c2,0.2,4,0.3,6.1,0.3c5.6,0,9.7-1.8,9.7-7.1c0-3.1-1.3-5.4-6-6.6%20l-2.6-0.7c-1.8-0.5-2.6-1-2.6-2.3c0-1.9,1.7-2.2,3.3-2.2c2.2,0,4.4,0.2,5.3,0.2c0.9,0.1,1.2,0,1.3-0.8l0.4-2.6c0-0.1,0-0.2,0-0.3%20c0-0.1-0.1-0.2-0.1-0.3s-0.1-0.1-0.2-0.2c-0.1,0-0.2-0.1-0.3-0.1c-2-0.2-4.1-0.3-6.1-0.3c-5.8,0-8.6,2.6-8.6,6.6%20c0,3.6,2,5.8,5.4,6.7l2.6,0.7c2.1,0.6,3,1.2,3,2.6c0,2-1.3,2.3-4.6,2.3c-1.5,0-4-0.2-4.9-0.3C75.3,30.8,75,30.9,74.9,31.7'/%3e%3cpath%20class='st1'%20d='M93.1,31.7l-0.4,2.7c-0.1,0.5,0.2,0.7,0.6,0.8c2,0.2,4,0.3,6.1,0.3c5.6,0,9.7-1.8,9.7-7.1c0-3.1-1.3-5.4-6-6.6%20l-2.6-0.7c-1.8-0.5-2.6-1-2.6-2.3c0-1.9,1.7-2.2,3.3-2.2c2.2,0,4.4,0.2,5.3,0.2c0.9,0.1,1.2,0,1.3-0.8l0.4-2.6c0-0.1,0-0.2,0-0.3%20c0-0.1-0.1-0.2-0.1-0.3c-0.1-0.1-0.1-0.1-0.2-0.2c-0.1,0-0.2-0.1-0.3-0.1c-2-0.2-4.1-0.3-6.1-0.3c-5.8,0-8.6,2.6-8.6,6.6%20c0,3.6,2,5.8,5.4,6.7l2.6,0.7c2.1,0.6,3,1.2,3,2.6c0,2-1.3,2.3-4.6,2.3c-1.5,0-4-0.2-4.9-0.3S93.1,30.9,93.1,31.7'/%3e%3cpath%20class='st1'%20d='M120.2,23.6l-0.3,1.5c-0.1,0.3-0.1,0.5-0.1,0.8c0,0.4,0.1,0.8,0.3,1.1l4.2,7.6c0.1,0.3,0.3,0.5,0.6,0.7%20c0.3,0.2,0.6,0.2,0.9,0.2h3.8c0.5,0,1.1-0.3,0.5-1.2l-5.1-8.6c1.7-1.1,3.7-2.7,3.7-6.1c0-4.4-2.5-6.9-7.9-6.9H113%20c-0.7,0-0.9,0.2-0.9,1v20.8c0,0.7,0.2,1,0.9,1h3.2c0.7,0,0.9-0.2,0.9-1V16.8h3.3c2.1,0,3.1,0.8,3.1,2.8c0.1,0.6,0,1.2-0.3,1.6%20c-0.3,0.5-0.7,0.9-1.3,1.1C120.9,22.7,120.6,22.3,120.2,23.6'/%3e%3c/svg%3e)