Earth\u2019s core is leaking, scientists say<\/span> <\/p>\n<\/p>\n<\/div>\n The weak magnetic field hadn\u2019t always been that way: The team examined similar rocks from South Africa that dated back more than 2 billion years and found, at that point in time, the Earth\u2019s magnetic field was as strong as it is today. <\/p>\n
Unlike now, Tarduno explained, back then the innermost part of Earth was liquid, not solid, influencing the way the magnetic field was generated. <\/p>\n
\u201cOver billions of years that process is becoming less and less efficient,\u201d he said. <\/p>\n
\u201cAnd by the time we get to the Ediacaran, the field is on its last legs. It\u2019s almost collapsing. But then fortunately for us it got cool enough that the inner core started to generate (strengthening the magnetic field).\u201d <\/p>\n
The emergence of the earliest complex life that would have wafted along the seafloor at this time is associated with a rise in oxygen levels. Some animals can survive at low levels of oxygen, such as sponges and microscopic animals, but larger animals with more complex bodies that move need more oxygen, Tarduno said. <\/p>\n
Traditionally, the rise in oxygen during this time has been attributed to photosynthetic organisms such as cyanobacteria, which produced oxygen, allowing it to build up in the water steadily over time, explained study coauthor Shuhai Xiao, a professor of geobiology at Virginia Tech. <\/p>\n
However, the new research suggested an alternative, or complementary, hypothesis involving an increased loss of hydrogen to space when the geomagnetic field was weak. <\/p>\n
\u201cThe magnetosphere shields the Earth from solar wind, thus holding the atmosphere to the Earth. Thus, a weaker magnetosphere means that lighter gases such as hydrogen would be lost from the Earth\u2019s atmosphere,\u201d Xiao added via email. <\/p>\n
Tarduno said multiple processes could have been taking place at once. <\/p>\n
\u201cWe do not challenge that one or more of these processes was happening concurrently. But the weak field may have allowed oxygenation to cross a threshold, aiding animal radiation (evolution),\u201d Tarduno said. <\/p>\n
Peter Driscoll, staff scientist at the Earth and Planets Laboratory at the Carnegie Institution for Science in Washington, DC, said he agreed with the study\u2019s findings on the weakness of Earth\u2019s magnetic field, but the claim that the weak magnetic field could have affected atmospheric oxygen and biological evolution was difficult to assess. He wasn\u2019t involved with the study. <\/p>\n
\u201cIt is hard for me to evaluate the veracity of this claim because the influence that planetary magnetic fields might have on climate is not very well understood,\u201d he said via email. <\/p>\n
Tarduno said that their hypothesis was \u201csolid,\u201d but proving a causative link could take decades of challenging work given how little is known about the animals that lived at this time. <\/p>\n
The geological analysis also revealed telling details about the innermost part of Earth\u2019s center. <\/p>\n
Estimates on when the planet\u2019s inner core may have solidified \u2014 when iron first crystallized at the center of the planet \u2014 once ranged from 500 million to 2.5 billion years ago. <\/p>\n
The research on the intensity of Earth\u2019s magnetic field suggests that the age of Earth\u2019s inner core is on the younger end of that timescale, solidifying after 565 million years ago and allowing Earth\u2019s magnetic shield to bounce back. <\/p>\n
\u201cThe observations appear to support the claim that the inner core first nucleated soon after this time, pushing the geodynamo (the mechanism that creates the magnetic field) from a weak, unstable state into a strong, stable dipolar field,\u201d Driscoll said. <\/p>\n
Tarduno said the recovery of the field strength after the Ediacaran, with the growth of the inner core, was probably important in preventing a drying of water-rich Earth. <\/p>\n
As for the bizarre animals of the Ediacaran, they had all disappeared by the following Cambrian Period, when the diversity of life exploded and the branches of the tree of life familiar today formed in a relatively short time. <\/p>\n<\/p>\n
This post appeared first on cnn.com<\/div>\n
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Earth\u2019s magnetic field plays a key role in making our planet habitable. The protective bubble over the atmosphere shields the planet from solar radiation, winds, cosmic rays and wild swings in temperature. However, Earth\u2019s magnetic field almost collapsed 591 million years ago, and this change, paradoxically, may have played a pivotal role in the blossoming <\/p>\n","protected":false},"author":1,"featured_media":2902,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[],"class_list":{"0":"post-2901","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-world-news"},"_links":{"self":[{"href":"https:\/\/digitaltradecenter.com\/index.php\/wp-json\/wp\/v2\/posts\/2901","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/digitaltradecenter.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/digitaltradecenter.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/digitaltradecenter.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/digitaltradecenter.com\/index.php\/wp-json\/wp\/v2\/comments?post=2901"}],"version-history":[{"count":0,"href":"https:\/\/digitaltradecenter.com\/index.php\/wp-json\/wp\/v2\/posts\/2901\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/digitaltradecenter.com\/index.php\/wp-json\/wp\/v2\/media\/2902"}],"wp:attachment":[{"href":"https:\/\/digitaltradecenter.com\/index.php\/wp-json\/wp\/v2\/media?parent=2901"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/digitaltradecenter.com\/index.php\/wp-json\/wp\/v2\/categories?post=2901"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/digitaltradecenter.com\/index.php\/wp-json\/wp\/v2\/tags?post=2901"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}