{"id":8885,"date":"2022-11-04T08:00:00","date_gmt":"2022-11-04T07:00:00","guid":{"rendered":"https:\/\/wp.unil.ch\/geoblog\/?p=8885"},"modified":"2022-11-04T09:43:51","modified_gmt":"2022-11-04T08:43:51","slug":"reaching-the-earths-mantle-a-dive-into-the-depths-of-its-continents","status":"publish","type":"post","link":"https:\/\/wp.unil.ch\/geoblog\/en\/2022\/11\/reaching-the-earths-mantle-a-dive-into-the-depths-of-its-continents\/","title":{"rendered":"Reaching the\u00a0\u00a0Earth&#8217;s mantle: a dive into the depths of its continents"},"content":{"rendered":"\n<div class=\"wp-block-group has-background is-layout-flow wp-block-group-is-layout-flow\" style=\"background-color:#f2f2f2\">\n<p><strong><strong>The continental crust makes up 41% of the Earth&#8217;s surface. Because of its thickness, its deepest areas remain unknown, although they play a fundamental role in the global cycles occurring between the Earth&#8217;s surface and the mantle.<\/strong> <a rel=\"noreferrer noopener\" href=\"https:\/\/www.dive2ivrea.org\/content\/project\" target=\"_blank\">The DIVE project<\/a>  ims to unveil the secrets of these transition<\/strong>&nbsp;processes<strong>. How?<\/strong>&nbsp;<strong>&nbsp;Thanks to two boreholes of about 1 km deep in the region of thegeological zone known as Ivrea-Verbano (Piedmont, Italy).<\/strong>&nbsp;<strong>&nbsp;After five years of preparation, UNIL scientists are finally on the ground.<\/strong><\/p>\n<\/div>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"DIVE : Plong\u00e9e dans les profondeurs de la cro\u00fbte terrestre\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/2A8y5p8C5Bk?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><figcaption><a href=\"https:\/\/applicationspub.unil.ch\/interpub\/noauth\/php\/Un\/UnPers.php?PerNum=1173368&amp;LanCode=8\">Gy\u00f6rgy Het\u00e9nyi<\/a>&nbsp;et<a href=\"https:\/\/applicationspub.unil.ch\/interpub\/noauth\/php\/Un\/UnPers.php?PerNum=68492&amp;LanCode=8\">&nbsp;Othmar M\u00fcntener<\/a>&nbsp;(professeurs \u00e0 l\u2019Institut des sciences de la Terre) nous font partager leur enthousiasme pour ce projet.<\/figcaption><\/figure>\n\n\n\n<h4 class=\"wp-block-heading\">Reaching for the mantle: a project that is more than sixty years old<\/h4>\n\n\n\n<p>The project to reach and cross&nbsp;the&nbsp;transition from&nbsp;the&nbsp;Earth&#8217;s crust to the upper mantle dates back more than 60 years.&nbsp;At the time, only indirect measurements gave a glimpse of&nbsp;&nbsp;the&nbsp;physico-chemical properties of the rocks that compose it. But attempts&nbsp;&nbsp;to&nbsp;gain access to&nbsp;the&nbsp;&nbsp;deep&nbsp;&nbsp;crust&nbsp;itself, by drilling&nbsp;&nbsp;at&nbsp;&nbsp;the&nbsp;bottom of the&nbsp;ocean or in&nbsp;&nbsp;the&nbsp;USSR, proved unsuccessful.&nbsp;The technical constraints and costs generated in relation&nbsp;to the&nbsp;expected results then slowed down initiatives to renew such attempts.&nbsp;&nbsp;<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p>What makes planet Earth unique? Together with water and life, it is plate tectonics.<\/p><cite>DIVE project<\/cite><\/blockquote>\n\n\n\n<p>In 2008,&nbsp;Luigi Burlini,&nbsp;a geologist at the ETHZ, discussed an original idea with Othmar M\u00fcntener. It is a question of using&nbsp;the&nbsp;Alps as a&nbsp;&#8220;shortcut&#8221; to the mantle.&nbsp;In&nbsp;the&nbsp;region of Ivrea-Verbano, the Earth&#8217;s&nbsp;mantle is at hand: it is about 3 km deep, following the alpine&nbsp;folding.&nbsp;It was&nbsp;the&nbsp;observation&nbsp;of&nbsp;high-density rocks and the rapid movement of seismic waves that revealed this singular&nbsp;situation&nbsp;covering an area&nbsp;about 70 km&nbsp;long (known as the&nbsp;<em>Ivrea Geophysical Body<\/em>).<\/p>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-28f84493 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:66.66%\">\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/schemaIVZ.jpg\"><img alt=\"\" loading=\"lazy\" decoding=\"async\" width=\"414\" height=\"333\" src=\"https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/schemaIVZ.jpg\" alt=\"\" class=\"wp-image-8859\" srcset=\"https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/schemaIVZ.jpg 414w, https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/schemaIVZ-300x241.jpg 300w\" sizes=\"auto, (max-width: 414px) 100vw, 414px\" \/><\/a><figcaption>Cross-section through the Ivrea Geophysical Body, according to knowledge in 2017. This diagram shows the wavevelocities estimated in two ways: in black the velocities derived from seismic refraction and density anomalies of the Berckhemer model in 1968; in orange the iso-velocities of the P waves interpolated from the tomography of local earthquakes by Diehl et al. (2009) . This analysis reveals that the shaded area is indeed the mantle that the DIVE project aims to achieve.<\/figcaption><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:33.33%\"><\/div>\n<\/div>\n\n\n\n<p>This&nbsp;original&nbsp;idea was taken up again to be concretized&nbsp;in&nbsp;2017 during a workshop bringing together more than 45 researchers&nbsp;in&nbsp;Baveno on the shores of Lake Majeur in Italy, by setting up the&nbsp;<a href=\"https:\/\/www.dive2ivrea.org\/\">DIVE project (Drilling the Ivrea-Verbano zonE<\/a>). Supported by the&nbsp;<a href=\"https:\/\/www.icdp-online.org\/home\/\">International Continental Scientific Drilling Program (ICDP),<\/a>&nbsp;DIVE is undertaking&nbsp;several scientific drillings in the Ivrea-Verbano area. His goal?&nbsp;Identify&nbsp;the&nbsp;physico-chemical&nbsp;properties&nbsp;of the&nbsp;crust-mantle transition,&nbsp;and&nbsp;better understand the processes that govern the formation and evolution of the lower&nbsp;continental&nbsp;crust.&nbsp;<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p>What does the bottom of the continental crust look like? And&nbsp;how deep can we find life within the crust?<\/p><cite>DIVE project<\/cite><\/blockquote>\n\n\n\n<p>DIVE is conducted by an international and multidisciplinary research&nbsp;group,&nbsp;covering the fields of geophysics, geochemistry, geodynamics, and petrology and rheology. Microbiologists&nbsp;are&nbsp;also involved: they are trying to find out how deep life can be found in the Earth&#8217;s crust.<\/p>\n\n\n\n<p>Other members of the FGSE (ISTE) are also involved in this project: Klaus Holliger (professor), Alexia Secr\u00e9tan, Kim Lemke, Zheng Luo (PhD students), Ludovic Baron (geophysical research engineer). Aurore Toussaint, Julien Reynes and Benjamin Klein, as well as&nbsp;researchers from the Universities of Bern,&nbsp;Mainz, Trieste,&nbsp;Pavia,&nbsp;Leoben, Grenoble, Georgia, and GFZ Berlin are also part of the scientific team taking turns on the site.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p>This type of project cannot be done alone or in pairs, because to have all the necessary skills, as well as the associated technology, you really need this interdisciplinary collaboration.<\/p><cite>Gy\u00f6rgy Het\u00e9nyi<\/cite><\/blockquote>\n\n\n\n<p>Gy\u00f6rgy Het\u00e9nyi will focus on the transition gradient between the mantle and the lower crust: what is its thickness&nbsp;and&nbsp;what are its physical and chemical properties?<\/p>\n\n\n\n<p>Othmar M\u00fcntener will be involved in petrological&nbsp;research and&nbsp;more specifically in the identification of the nature of the rocks that form at the interface between the mantle and the Earth&#8217;s crust.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/manteau.jpg\"><img alt=\"\" loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"596\" src=\"https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/manteau-1024x596.jpg\" alt=\"\" class=\"wp-image-8861\" srcset=\"https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/manteau-1024x596.jpg 1024w, https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/manteau-300x175.jpg 300w, https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/manteau-768x447.jpg 768w, https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/manteau-1536x894.jpg 1536w, https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/manteau-1320x768.jpg 1320w, https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/manteau.jpg 1920w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><figcaption>From 2017 to 2022, numerous preliminary studies combining different geophysical methods were carried out, in particular to determine the location of boreholes. The proximity of the mantle to a depth of about 1 km below sea level at the surface was thus confirmed and modeled in 3 dimensions by Matteo Scarponi during his PhD at ISTE, The relief shape represents the mantle surface that &#8220;rises&#8221; towards the surface of the Earth&#8217;s crust according to the results of Matteo Scarponi, Printed at a scale of 1:1 million. Researchers from GFZ Potsdam and Montanuniversit\u00e4t Leoben are currently refining this image via higher resolution active seismic studies.<\/figcaption><\/figure>\n\n\n\n<h4 class=\"wp-block-heading\">The big day: the first drilling and extraction of the first rocks<\/h4>\n\n\n\n<p>After more than five years of preparation,&nbsp;drilling finally began on October 6, 2022&nbsp;in&nbsp;Ornavasso in the Osso l a. At first, the pace is slow. The team ensures the verticality of the drill and does not damage the first layers of soft&nbsp;soil. Subsequently, the speed should be increased&nbsp;to&nbsp;about 1 meter per hour \u2013 or 15 to 20 meters s per day ideally. So far, thefirst steps have been encouraging.&nbsp;The extracted carrots are exploitable at more than 95%, a very high&nbsp;yield!<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/carottes.jpg\"><img alt=\"\" loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"641\" src=\"https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/carottes-1024x641.jpg\" alt=\"\" class=\"wp-image-8863\" srcset=\"https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/carottes-1024x641.jpg 1024w, https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/carottes-300x188.jpg 300w, https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/carottes-768x481.jpg 768w, https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/carottes.jpg 1124w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><figcaption>The cores are directly photographed and scanned to identify the rocks that compose them and evaluate the progress of the drilling. They will then be sawn in half in the long direction. One half will be used for chemical and physical analysis and the other half will be archived in Germany. Above is some of the first cores taken, photographed and listed (photo credit: Luca Ziberna, DIVE project).<\/figcaption><\/figure>\n\n\n\n<p>The borehole will have another advantage. Fine logging&nbsp;instruments&nbsp;can be placed&nbsp;there. They&nbsp;will measure the&nbsp;electrical,&nbsp;thermal&nbsp;and&nbsp;seismic&nbsp;properties&nbsp;of the terrain at a depth rarely reached, and will make a video recording along the hole. This device,&nbsp;associated with&nbsp;a continuum of&nbsp;several hundred meters of cores through the deep crust, constitute a unique dataset to date.<\/p>\n\n\n\n<p>The organization of this work is complex and interactions are continuous with the field. A team of 6 to 7 people remains permanently&nbsp;on&nbsp;site to monitor the drilling, analyze the extracted cores, list them on a digital interface or collect fragments for microbiologists. Questions&nbsp;or&nbsp;unforeseen events arise regularly, whether at technical level&nbsp;(purchase or adaptation of equipment) or scientific level (identification of minerals and structures). You&nbsp;have to be&nbsp;very responsive because drilling must be able&nbsp;to&nbsp;continue quickly.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/flyer_DIVE_anglais.jpg\"><img alt=\"\" loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"684\" src=\"https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/flyer_DIVE_anglais-1024x684.jpg\" alt=\"\" class=\"wp-image-8891\" srcset=\"https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/flyer_DIVE_anglais-1024x684.jpg 1024w, https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/flyer_DIVE_anglais-300x201.jpg 300w, https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/flyer_DIVE_anglais-768x513.jpg 768w, https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/flyer_DIVE_anglais-1536x1027.jpg 1536w, https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/flyer_DIVE_anglais-1320x882.jpg 1320w, https:\/\/wp.unil.ch\/geoblog\/files\/2022\/11\/flyer_DIVE_anglais.jpg 1794w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><figcaption>The drilling activities arouse the curiosity of the inhabitants and visitors of the site. Here is part&nbsp;of&nbsp;the leaflet that describes the project and its objectives, for the inhabitants and visitors of the region of Ivre&nbsp;a-Verbano. Public visits will also be carried out on site.<\/figcaption><\/figure>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p>Everyone at the drilling site was super happy&#8230;. When you see the rocks coming out, it is the direct result of these 5 years of investment. It&#8217;s really satisfying.<\/p><cite>Othmar M\u00fcntener<\/cite><\/blockquote>\n\n\n\n<h4 class=\"wp-block-heading\">A gratifying first step &#8230; who prepares the second<\/h4>\n\n\n\n<p>The results of the research carried out in the coming years on the material obtained will determine&nbsp;the&nbsp;organization&nbsp;and&nbsp;timing&nbsp;of the&nbsp;second phase&nbsp;of the&nbsp;project, namely a&nbsp;3-4&nbsp;km&nbsp;borehole in search&nbsp;of the&nbsp;Moho (the&nbsp;transition between the crust and the mantle).<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p><em>From a scientific point of view, we are quite sure that<\/em>&nbsp;<em>we will have surprises either during the drilling or the analyses that will follow<\/em>.<\/p><cite>Gy\u00f6rgy Het\u00e9nyi&nbsp;&amp; Othmar M\u00fcntener<\/cite><\/blockquote>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-28f84493 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<div class=\"wp-block-group has-background is-layout-flow wp-block-group-is-layout-flow\" style=\"background-color:#f2f2f2\">\n<h4 class=\"wp-block-heading\">For more information<\/h4>\n\n\n\n<ul class=\"wp-block-list\"><li><a href=\"https:\/\/www.dive2ivrea.org\/\"><a href=\"https:\/\/www.dive2ivrea.org\/\">DIVE Project<\/a><\/a><\/li><li><a href=\"https:\/\/www.icdp-online.org\/projects\/world\/europe\/ivrea-italy\/daily-news\/\"><a href=\"https:\/\/www.icdp-online.org\/projects\/world\/europe\/ivrea-italy\/daily-news\/\">Monitoring\u00a0the progress of the work on site<\/a><\/a><\/li><\/ul>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\"><\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>The continental crust makes up 41% of the Earth&#8217;s surface. Because of its thickness, its deepest areas remain unknown, although they play a fundamental role in the global cycles occurring between the Earth&#8217;s surface and the mantle. The DIVE project ims to unveil the secrets of these transition&nbsp;processes. How?&nbsp;&nbsp;Thanks to two boreholes of about 1 [&hellip;]<\/p>\n","protected":false},"author":1002284,"featured_media":8884,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"","_seopress_titles_title":"","_seopress_titles_desc":"","_seopress_robots_index":"","footnotes":"","_links_to":"","_links_to_target":""},"categories":[67094,67041],"tags":[67132,67118],"class_list":{"0":"post-8885","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-portraits-of-projects","8":"category-research-at-work","9":"tag-gyorgy-hetenyi-en","10":"tag-othmar-muntener-2-en"},"_links":{"self":[{"href":"https:\/\/wp.unil.ch\/geoblog\/en\/wp-json\/wp\/v2\/posts\/8885","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wp.unil.ch\/geoblog\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wp.unil.ch\/geoblog\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wp.unil.ch\/geoblog\/en\/wp-json\/wp\/v2\/users\/1002284"}],"replies":[{"embeddable":true,"href":"https:\/\/wp.unil.ch\/geoblog\/en\/wp-json\/wp\/v2\/comments?post=8885"}],"version-history":[{"count":0,"href":"https:\/\/wp.unil.ch\/geoblog\/en\/wp-json\/wp\/v2\/posts\/8885\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/wp.unil.ch\/geoblog\/en\/wp-json\/wp\/v2\/media\/8884"}],"wp:attachment":[{"href":"https:\/\/wp.unil.ch\/geoblog\/en\/wp-json\/wp\/v2\/media?parent=8885"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wp.unil.ch\/geoblog\/en\/wp-json\/wp\/v2\/categories?post=8885"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wp.unil.ch\/geoblog\/en\/wp-json\/wp\/v2\/tags?post=8885"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}