Smart phones could be used to detect earthquakes

first_imgThe cellphone in your pocket could soon save you from an earthquake. Researchers have shown that it is possible to use GPS data from smart phones to detect tremors, potentially providing an early warning system to those who have not yet been hit.”What’s really nice about this work is they are using sensors that people carry around anyway,” says geophysicist Kristine Larson of the University of Colorado, Boulder. “It could be very, very useful.”In the moments before an earthquake, a few extra seconds can mean the difference between life and death. With a little bit of warning, people can take shelter, nuclear power plants can take last-minute precautions, and natural gas utilities can shut down pipelines. Japan has an early warning system that relies on more than 1000 seismometers throughout the country, which saved lives during the magnitude-9 Tohoku earthquake that hit in 2011. A similar system exists in Mexico, and another is under study in California. But such systems are expensive and time-consuming to install and maintain, making cellphones an attractive alternative, especially for earthquake-prone countries in the developing world.Sign up for our daily newsletterGet more great content like this delivered right to you!Country *AfghanistanAland IslandsAlbaniaAlgeriaAndorraAngolaAnguillaAntarcticaAntigua and BarbudaArgentinaArmeniaArubaAustraliaAustriaAzerbaijanBahamasBahrainBangladeshBarbadosBelarusBelgiumBelizeBeninBermudaBhutanBolivia, Plurinational State ofBonaire, Sint Eustatius and SabaBosnia and HerzegovinaBotswanaBouvet IslandBrazilBritish Indian Ocean TerritoryBrunei DarussalamBulgariaBurkina FasoBurundiCambodiaCameroonCanadaCape VerdeCayman IslandsCentral African RepublicChadChileChinaChristmas IslandCocos (Keeling) IslandsColombiaComorosCongoCongo, The Democratic Republic of theCook IslandsCosta RicaCote D’IvoireCroatiaCubaCuraçaoCyprusCzech RepublicDenmarkDjiboutiDominicaDominican RepublicEcuadorEgyptEl SalvadorEquatorial GuineaEritreaEstoniaEthiopiaFalkland Islands (Malvinas)Faroe IslandsFijiFinlandFranceFrench GuianaFrench PolynesiaFrench Southern TerritoriesGabonGambiaGeorgiaGermanyGhanaGibraltarGreeceGreenlandGrenadaGuadeloupeGuatemalaGuernseyGuineaGuinea-BissauGuyanaHaitiHeard Island and Mcdonald IslandsHoly See (Vatican City State)HondurasHong KongHungaryIcelandIndiaIndonesiaIran, Islamic Republic ofIraqIrelandIsle of ManIsraelItalyJamaicaJapanJerseyJordanKazakhstanKenyaKiribatiKorea, Democratic People’s Republic ofKorea, Republic ofKuwaitKyrgyzstanLao People’s Democratic RepublicLatviaLebanonLesothoLiberiaLibyan Arab JamahiriyaLiechtensteinLithuaniaLuxembourgMacaoMacedonia, The Former Yugoslav Republic ofMadagascarMalawiMalaysiaMaldivesMaliMaltaMartiniqueMauritaniaMauritiusMayotteMexicoMoldova, Republic ofMonacoMongoliaMontenegroMontserratMoroccoMozambiqueMyanmarNamibiaNauruNepalNetherlandsNew CaledoniaNew ZealandNicaraguaNigerNigeriaNiueNorfolk IslandNorwayOmanPakistanPalestinianPanamaPapua New GuineaParaguayPeruPhilippinesPitcairnPolandPortugalQatarReunionRomaniaRussian FederationRWANDASaint Barthélemy Saint Helena, Ascension and Tristan da CunhaSaint Kitts and NevisSaint LuciaSaint Martin (French part)Saint Pierre and MiquelonSaint Vincent and the GrenadinesSamoaSan MarinoSao Tome and PrincipeSaudi ArabiaSenegalSerbiaSeychellesSierra LeoneSingaporeSint Maarten (Dutch part)SlovakiaSloveniaSolomon IslandsSomaliaSouth AfricaSouth Georgia and the South Sandwich IslandsSouth SudanSpainSri LankaSudanSurinameSvalbard and Jan MayenSwazilandSwedenSwitzerlandSyrian Arab RepublicTaiwanTajikistanTanzania, United Republic ofThailandTimor-LesteTogoTokelauTongaTrinidad and TobagoTunisiaTurkeyTurkmenistanTurks and Caicos IslandsTuvaluUgandaUkraineUnited Arab EmiratesUnited KingdomUnited StatesUruguayUzbekistanVanuatuVenezuela, Bolivarian Republic ofVietnamVirgin Islands, BritishWallis and FutunaWestern SaharaYemenZambiaZimbabweI also wish to receive emails from AAAS/Science and Science advertisers, including information on products, services and special offers which may include but are not limited to news, careers information & upcoming events.Required fields are included by an asterisk(*)Previous studies of crowdsourcing earthquake early warning systems have relied on phones’ accelerometers, which estimate the phone’s movement, rather than GPS tracking, which locates the absolute position of the phone using satellites. Scientific GPS stations have already been used to detect earthquakes, but the new study found that even consumer devices with GPS could be useful for crowdsourcing warnings. And as more and more of our devices integrate GPS navigation, including vehicles, increasing amounts of data could boost the sensitivity of such efforts.To understand whether smart phones and other consumer devices could detect quakes with GPS at all, researchers tested the sensitivity of such devices. Cell phones typically use a coarser method of positioning than do the most sensitive scientific instruments, which take advantage of more information encoded in the GPS signal. The scientists studied the accuracy of cellphone GPS by shaking a phone and comparing its recorded displacements with a more accurate scientific device. And by monitoring the phone for movement while holding it stationary, they measured the chance for false alarms. The researchers determined that consumer GPS devices could detect earthquakes of magnitude 7 and above, allowing possible warnings for people located away from the epicenter of the most destructive quakes, they report today in Science Advances.Next, the researchers tested the concept using a computer simulation of a magnitude-7 earthquake near Oakland, California, on the Hayward fault, a likely spot for future tremors that runs through the San Francisco Bay Area. By simulating the typical response of cellphones to shaking, they estimated the signals in cellphones near the epicenter. In the researchers’ system, a quake “triggers” a phone if it and four neighboring devices all record simultaneous movements greater than 5 centimeters. To weed out coincidences, the system only issues an alert if more than 100 devices see such triggers. Assuming data from 0.2% of the population—less than 5000 people—the system was able to detect the simulated earthquake within 5 seconds, a speed that would have allowed a few seconds of warning before the strongest shaking began in San Francisco and 10 seconds before it began in San Jose, providing time for children to get under their desks and for trains to put on the breaks.The researchers then tested their system with real data from the Tohoku quake. The team used an array of 462 GPS stations spread across Japan to approximate the data that would come from cellphones. Although these scientific instruments are more precise than cellphones, they record lower quality data as well, which is similar to data from consumer devices. In this scenario, the researchers set the bar for detection so that the chances of a false alarm would be about one in 2 million. The system would have detected the earthquake 77 seconds after it began, which would have allowed a warning of about 10 seconds before the earthquake reached Tokyo. What’s more, it would have allowed several minutes’ warning before the accompanying tsunami. Although scientific detection systems might provide even faster warnings, these systems might be useful in places without warning systems.As technology advances and more devices integrate GPS tracking, the system will become more useful, says study author Benjamin Brooks, an earthquake scientist at the U.S. Geological Survey in Menlo Park, California. “It’s not really just about smart phones, it’s about all sorts of Internet-connected devices that have positioning associated with them. … We think the numbers are going to be so large that you could be very liberal with your criteria for using a specific device.” Detection with cellphones is difficult because users are constantly moving them around, but with enough data, the system could rely on devices that weren’t in motion before the quake, improving warning capabilities.However, computational earthquake seismologist Jesse Lawrence of Stanford University in Palo Alto, California, points out a few challenges to the approach. Using GPS drains phone batteries, so data collection might need to be restricted to times when phones are recharging, meaning that few phones will be operating during the day. And the software has to deal with phones behaving unpredictably during an earthquake, such as falling from a table onto the floor. Because of that, Lawrence says, “the way that they’ve done the simulations, I would argue, doesn’t really match real world.” But he is optimistic about the possibilities for this technology in the future. “It’s great research, and this is the first step.”last_img read more

Volunteer Coders Partner With San Francisco to Clear 9300 Marijuana Arrest Records

first_img –shares Green Entrepreneur Podcast People arrested with a joint long ago were saddled with criminal records for decades. Marijuana legalization isn’t just about stopping arrests under War on Drugs-era laws for cannabis possession. In California, it’s also about clearing the records of thousands who were arrested during that era and still struggle with the stigma of a criminal record for actions that ara legal now.With the help of a volunteer organization that uses technology to make governments more efficient, San Francisco officials plan to expunge records of 9,300 marijuana-related convictions that go back as far 1975. San Francisco District Attorney George Gascón called expunging the records “the morally right thing to do,” according to the Los Angeles Times. He then added, “If you have a felony conviction, you are automatically excluded in so many ways from participating in your community.”Related: Holy Smokes! Tel-Aviv’s Cannabis Industry Is Lighting UpNo need to ask.The district attorney’s office has set up a process which allows people to ask for a conviction to be expunged, but only 23 people had applied, according to NPR. Gascon said that process was cumbersome and decided to just get on with it. The district attorney’s office partnered with Code for America, a nonprofit group of coding volunteers who take on projects that make government more efficient. They focus on  issues of criminal justice, the social safety net and workforce development.For example, they are running pilot projects in five states to make social benefits more accessible to thousands of poor Americans.In the San Francisco situation, the issue was criminal justice. Gascón’s people started about a year ago to go through cases by hand and had found about 1,000 to expunge. Volunteers with Code for America were able to create a program in minutes that searched through criminal records back to 1975 and found thousands more to clear.San Francisco is the first to take on this issue in a substantive way (i.e., doing something rather than talking about it). Los Angeles may not be far behind. There have been about 40,000 felony convictions for marijuana-related offenses in Los Angeles County since 1993, many of which might be eligible, according to the Times.Related: New Jersey Inches Closer to Legalizing Marijuana Without Voter ReferendumWar on Drugs vs. MinoritiesPoliticians across the country are now arguing that marijuana legalization is a social justice issue because the War on Drugs disproportionately impacted minority communities. San Francisco provides a good example of how this played out, statistically.The “Cannabis Equity Report” done by San Francisco (the city and county) found that in 2000, 7.8 percent of the population in San Francisco was black, but 41 percent of all marijuana-related arrests involved black suspects. By 2011, arrests involving black San Franciscans “hovered around 50 percent” of all arrests, according to the report.In a statement on the issue from last year, Gascón said that a “criminal conviction can be a barrier to employment, housing and other benefits, so instead of waiting for the community to take action, we’re taking action for the community.”To stay up to date on the latest marijuana-related news make sure to like dispensaries.com on Facebook Legal Marijuana Add to Queue Image credit: Steven Clevenger | Getty Images Next Article Listen Now dispensaries.com Volunteer Coders Partner With San Francisco to Clear 9,300 Marijuana Arrest Records Each week hear inspiring stories of business owners who have taken the cannabis challenge and are now navigating the exciting but unpredictable Green Rush. 3 min read Guest Writer Opinions expressed by Entrepreneur contributors are their own. Easy Search. Quality Finds. Your partner and digital portal for the cannabis community. March 12, 2019last_img read more