For centuries, scientists have tried to answer the question, \u201cWhat\u2019s the Earth made of?\u201d While drilling projects and geological studies have revealed clues about the planet\u2019s crust, the deeper layers remain largely inaccessible.<\/p>\n
Now, researchers at Queen\u2019s University are turning to an unlikely source of information\u2014subatomic particles known as geoneutrinos\u2014to probe the planet\u2019s interior.<\/p>\n
The research comes from a Queen\u2019s-led team working with the SNO+<\/a> neutrino detector at SNOLAB<\/a> in Sudbury, Ontario. Located two kilometres underground to shield it from radiation and other interference, the detector is designed to capture faint flashes of light produced when neutrinos interact with a liquid scintillator<\/a>, a solution of organic compounds that emits light when exposed to radiation, inside a spherical tank.<\/p>\n In an interview with The Journal, Alex Wright<\/a>, associate professor in the Department of Physics, Engineering Physics, and Astronomy at Queen\u2019s, defined a geoneutrino.<\/p>\n \u201cGeoneutrinos are a type of antineutrino, subatomic particles that are produced by decay of trace radioisotopes in the Earth.\u201d<\/p>\n Since geoneutrinos are so tiny, nearly a billion times<\/a> smaller than a proton, they can travel through solid matter almost unhindered, and they carry information about the chemical composition of the planet\u2019s interior. The particles offer scientists a rare window into the planet\u2019s interior, which is otherwise impossible to sample directly.<\/p>\n \u201cWe can sample the surface, and with a couple of kilometers down from the surface, we can drill sample holes and try to estimate beyond that. But the content of the mantle and the core, the inner layers of the earth, really isn\u2019t known,\u201d Wright noted.<\/p>\n By measuring geoneutrinos, researchers can infer the presence of radioactive materials deep underground.<\/p>\n \u201cOne clue we can gain into what the composition is, is by looking at how many of these antineutrinos there are, which gives us some information about what\u2019s going on in the middle of the Earth,\u201d Wright shared.<\/p>\n According to Wright, understanding these particles could also help answer a long-standing question about the planet\u2019s heat.<\/p>\n \u201cWe know from geophysical measurements that the Earth is giving off terawatts of heat, but we don\u2019t know whether the Earth is still cooling down or not. By measuring the geoneutrino flux, we hope to figure out whether there\u2019s enough radioactivity in the Earth to be supplying the heat or whether the Earth is still cooling.\u201d<\/p>\n However, detecting these particles is challenging. According to Dr. James Page, a postdoctoral researcher in the Department of Physics, Engineering Physics, and Astronomy, and the principal analyst on the project, the SNO+ detector at SNOLAB is designed to overcome these obstacles.<\/p>\n \u201cOne of the challenges is the rate of geo-neutrinos is really low, so they get drowned out by all sorts of radioactive backgrounds,\u201d Page said.<\/p>\n \u201cThe other difficult hurdle to overcome is that they\u2019re all very low in energy. So, you need really sensitive detectors [\u2026] these are what are called liquid scintillator detectors\u2026to be able to pick out these really low energy events,\u201d Page added. \u201cBut the detector is very clean. So, there are very low ambient background rates. It\u2019s deep underground, so you get less cosmic rays coming in.\u201d<\/p>\n The results mark the first time geoneutrinos have been detected in Canada, making SNO+ the third detector in the world to measure them, following similar experiments in Japan and Italy.<\/p>\n Observations from different regions are crucial for understanding how geological structures, such as the Canadian Shield<\/a>, affect the particles being detected. Situated on the Canadian Shield, a vast region of Precambrian rock, the detector sits above a thick section of Earth\u2019s crust.<\/p>\n \u201cThe Canadian Shield is really thick. So, the crust there is around 40 kilometres thick, which is significantly thicker than at the other two sites where geoneutrinos have been measured,\u201d Page noted.<\/p>\n The project brings together particle physicists and geologists, combining expertise from both fields to interpret what these signals reveal about the Earth\u2019s internal structure. The study\u2019s findings were first presented at the Neutrino Geosciences 2025<\/a> conference hosted by Queen\u2019s.<\/p>\n By comparing measurements from different parts of the world, researchers hope to determine whether the particles originate in the planet\u2019s crust or deeper layers such as the mantle.<\/p>\n Researchers say studying geoneutrinos could answer fundamental questions about the planet, including how much of Earth\u2019s heat comes from radioactive decay and how much remains from its formation billions of years ago. It may also shed light<\/a> on whether the mantle is chemically uniform or made up of distinct regions with different compositions.<\/p>\n For scientists studying the deep Earth, geoneutrinos drifting silently through the planet may offer one of the clearest windows yet into a place we can\u2019t reach.<\/p>\n Tags<\/p>\n \n Core<\/a>, earth<\/a>, Geology<\/a>, Geoneutrino<\/a> <\/p>\n All final editorial decisions are made by the Editor(s) in Chief and\/or the Managing Editor. Authors should not be contacted, targeted, or harassed under any circumstances. If you have any grievances with this article, please direct your comments to journal_editors@ams.queensu.ca<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"For centuries, scientists have tried to answer the question, \u201cWhat\u2019s the Earth made of?\u201d While drilling projects and…\n","protected":false},"author":2,"featured_media":518823,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[49,48,12322,1677,10753,204939,66],"class_list":["post-518822","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-ca","tag-canada","tag-core","tag-earth","tag-geology","tag-geoneutrino","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/518822","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=518822"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/518822\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/518823"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=518822"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=518822"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=518822"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}