{"id":239521,"date":"2026-09-14T10:23:49","date_gmt":"2026-09-14T02:23:49","guid":{"rendered":"https:\/\/www.cpr.cuhk.edu.hk\/?post_type=press&p=239521"},"modified":"2026-09-14T12:29:18","modified_gmt":"2026-09-14T04:29:18","slug":"cuhk-led-study-reveals-why-mercurys-young-plains-have-the-most-wrinkles-ongoing-mantle-activity-continues-to-shape-the-planets-surface","status":"publish","type":"press","link":"https:\/\/www.cpr.cuhk.edu.hk\/en\/press\/cuhk-led-study-reveals-why-mercurys-young-plains-have-the-most-wrinkles-ongoing-mantle-activity-continues-to-shape-the-planets-surface\/","title":{"rendered":"CUHK-led study reveals why Mercury\u2019s young plains have the most \u201cwrinkles\u201d Ongoing mantle activity continues to shape the planet\u2019s surface"},"content":{"rendered":"","protected":false},"featured_media":0,"template":"","tags":[],"class_list":["post-239521","press","type-press","status-publish","hentry"],"acf":{"title_alt":"CUHK-led study reveals why Mercury\u2019s young plains have the most \u201cwrinkles\u201d\r\nOngoing mantle activity continues to shape the planet\u2019s surface","sub_title_alt":"","press_date":"20260914","keep":false,"details":"

A research team led by The Chinese University of Hong Kong (CUHK) has uncovered new evidence that Mercury\u2019s interior remained geologically active far longer than previously believed. Published in the prestigious international scientific journal Nature Communications<\/em><\/a>, the study reveals that the relatively young plains near Mercury\u2019s north pole exhibit more pronounced crustal compression and deformation than older regions, caused by an upwelling of hot rock from the deep mantle once occurred beneath the area. This challenges the long-standing theory that Mercury\u2019s landscape was shaped dominantly by the planet\u2019s cooling and contraction.<\/p>\r\n

Mapping Mercury\u2019s surface reveals anomalous tectonic deformation<\/strong><\/p>\r\n

Mercury is the smallest planet in the Solar System and the closest to the Sun. The evolution of Mercury\u2019s landscape shares similarities with other terrestrial planets: as its hot interior slowly cooled over time, the whole planet contracted, causing its rocky outer shell to buckle into long cliffs and ridges \u2013 much like the skin of a drying apple.<\/p>\r\n

The study focused on the Northern Smooth Plains, a vast volcanic plain near Mercury\u2019s north pole that covers about 7% of the planet\u2019s surface. Formed roughly 3.7 billion years ago, it is geologically young by Mercury\u2019s standards. Under existing theories, most of the planet\u2019s shrinking had already occurred, meaning this newer surface should have experienced less contractional deformation. The CUHK-led team mapped cliffs and ridges across the whole planet and measured the degree of crustal compression. Surprisingly, the results were the opposite of what they expected: this young plain turned out to be the most heavily wrinkled region on Mercury, indicating that cooling-driven contraction alone cannot fully explain the formation of the Northern Smooth Plains.<\/p>\r\n

Mantle upwelling identified as another key driver of surface evolution<\/strong><\/p>\r\n

To investigate the cause of this anomaly, the team combined measurements of Mercury\u2019s gravity and surface height with computer simulations of its interior. The results indicate that regional mantle activity can continue to shape Mercury\u2019s surface morphology.<\/p>\r\n

At the centre of the plain sits a broad, gentle bulge called the Northern Rise, which the study attributes to a plume of hot, buoyant rock that rose from about 350 km below the surface. Unable to breach the planet\u2019s rigid outer shell, this rising rock spread out sideways beneath the crust, forming a flat layer roughly 730 km wide. That layer pushed up the centre of the plain and stretched it slightly, while pinching and wrinkling the surrounding plains.<\/p>\r\n

Even after the hot rock cooled and the bulge began to sag, the compression did not stop. The slopes and residual stresses left behind continued to fracture the surface over a very long time, explaining why some cliffs and cracks in this region look surprisingly young and fresh.<\/p>\r\n

\u201cThe damage forms a clear bull\u2019s\u2011eye around the Northern Rise,\u201d said Professor Zhan Yan<\/strong>, the study\u2019s corresponding author and Ng Yin Ying Assistant Professor of Geophysics at CUHK\u2019s Department of Earth and Environmental Sciences. \u201cThat pattern points to a heat source deep below, and it changes how we read Mercury\u2019s cliffs and ridges.\u201d<\/p>\r\n

\u201cMercury is often written off as geologically dead,\u201d said Dr Xie Jingchun<\/strong>, the study\u2019s first author and a postdoctoral fellow at CUHK\u2019s Department of Earth and Environmental Sciences. \u201cWe show that deep inside, something kept working on the surface long after the planet\u2019s main thermal evolution had faded \u2013 much like a footprint that keeps pressing into the ground after the foot has already lifted.\u201d<\/p>\r\n

Broad implications for terrestrial planetary science <\/strong><\/p>\r\n

The team believes this study provides a new framework for understanding tectonic features on Mercury that can be applied to other celestial bodies. Similar deep-seated upwellings are suspected on Mars and Venus, but previous studies have rarely linked them so clearly to surface cracks and cliffs. By integrating surface mapping with interior dynamic modelling, this research demonstrates how rocky planets cool and shrink, while localised deep-mantle heat sources can rejuvenate geological activity for billions of years.<\/p>\r\n

\u201cIt is striking that a process starting from such depths can leave such a neat pattern at the surface,\u201d said co\u2011author Dr Zhang Jian<\/strong> of The University of Hong Kong. \u201cIt shows that the interior and the surface of Mercury stayed connected for far longer than we previously assumed.\u201d<\/p>\r\n

The full text of the research paper in Nature Communications<\/em> can be accessed here: https:\/\/www.nature.com\/articles\/s41467-026-74975-0<\/a><\/p>\r\n

About the study<\/strong><\/p>\r\n

This research was supported by the Hong Kong Research Grants Council, the National Natural Science Foundation of China and the Ministry of Science and Technology of China, among others. The authors are Xie Jingchun (CUHK), Zhan Yan (CUHK, corresponding author), Gong Shengxia (Shanghai Astronomical Observatory, Chinese Academy of Sciences), Huang Chengli (Shanghai Astronomical Observatory; School of Astronomy and Space Science, University of Chinese Academy of Sciences) and Zhang Jian (NWU-HKU Joint Centre of Earth and Planetary Sciences, The University of Hong Kong).<\/p>","show_as_achievement":false,"achievement_category":[],"show_as_clarification":false,"show_as_announcement":false,"photos":[{"photo":239518,"caption":"Mercury in enhanced colour, built from NASA MESSENGER images. The colours are not what your eye would see \u2013 they are boosted to bring out differences in the rocks at the surface. (Credit: NASA\/Johns Hopkins University Applied Physics Laboratory\/Carnegie Institution of Washington)"},{"photo":239519,"caption":"A cliff called Carnegie Rupes, almost 2 km tall, slices through a crater 105 km wide. Cliffs like this form when a planet\u2019s surface is squeezed. Colours show height (red = high, blue = low). (Credit: NASA\/Johns Hopkins University Applied Physics Laboratory\/Carnegie Institution of Washington)"},{"photo":239517,"caption":"How the plains changed. (a) The surface stretches and lava erupts as hot mantle rises. (b) As the rising rock fades, the surface is squeezed instead. (Credit: Xie et al., Nature Communications, 2026)"},{"photo":239520,"caption":"Dr Xie Jingchun (left) and Professor Zhan Yan discuss their Mercury research."}],"attachments":null,"video_source":"","video_file":"","add_play_button":false,"video_caption":"","show_migration":false,"original_id":0,"photos_original":null,"attachments_original":null},"publishpress_future_workflow_manual_trigger":{"enabledWorkflows":[]},"_links":{"self":[{"href":"https:\/\/www.cpr.cuhk.edu.hk\/en\/wp-json\/wp\/v2\/press\/239521","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.cpr.cuhk.edu.hk\/en\/wp-json\/wp\/v2\/press"}],"about":[{"href":"https:\/\/www.cpr.cuhk.edu.hk\/en\/wp-json\/wp\/v2\/types\/press"}],"version-history":[{"count":3,"href":"https:\/\/www.cpr.cuhk.edu.hk\/en\/wp-json\/wp\/v2\/press\/239521\/revisions"}],"predecessor-version":[{"id":239570,"href":"https:\/\/www.cpr.cuhk.edu.hk\/en\/wp-json\/wp\/v2\/press\/239521\/revisions\/239570"}],"wp:attachment":[{"href":"https:\/\/www.cpr.cuhk.edu.hk\/en\/wp-json\/wp\/v2\/media?parent=239521"}],"wp:term":[{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cpr.cuhk.edu.hk\/en\/wp-json\/wp\/v2\/tags?post=239521"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}