Earth Science: An Essential Foundation for Humanity’s Response to Challenges

    As humanity’s understanding of and exploitation and utilization of the natural world continue to deepen, the importance of Earth sciences has become increasingly prominent. Earth sciences have now emerged as a crucial foundation for effectively addressing a host of challenges facing human economic and social development, including energy security, resource security, climate change, ecological environment, and urbanization.

　　This article is primarily based on a systematic monitoring and compilation of the latest developments in Earth science research, as reflected in key scientific strategic plans, significant technological advances, and important scientific publications from 2015. It selects and summarizes the major cutting-edge scientific issues and technological development trends in the field of Earth science for the year 2015, for the reference of readers.

　　Development Trends in Solid Earth Science

　　1. Research on deep mantle plumes continues to intensify and has achieved significant breakthroughs.

　　Mantle plumes have long been a hot topic in geological research. Using supercomputers, U.S. geophysicists analyzed full-wave seismic data from 273 major earthquakes that occurred worldwide over the past two decades and created high-resolution images of mantle plumes, producing an unprecedentedly precise simulation of Earth’s interior. They investigated the relationship between deep mantle plumes and volcanic hotspots and, for the first time, provided direct evidence of the existence of mantle plumes. The journal *Science* commented on this groundbreaking research, listing it as one of the top ten scientific breakthroughs of 2015. The journal also noted that this significant achievement was made possible by the application of “full-waveform tomography” simulation technology.

　　In addition, scientists at the Swiss Federal Institute of Technology in Zurich have found through simulation studies that plate motions triggered by mantle plumes likely prevailed extensively during the Precambrian era (about 3 billion years ago), leading them to conclude that mantle plumes were responsible for Earth’s earliest plate tectonic movements.

　　2. Research on the formation and evolution of the Earth’s crust has yielded several important insights.

　　Scientists at the University of Iceland are systematically observing and studying the crustal formation processes occurring in Iceland using GPS and satellite positioning. They have elucidated how intermittent accumulations of magma between volcanic centers effectively facilitate long-distance transport and distribution, thereby giving rise to the formation of new upper crust along various plate boundaries. Scholars at Princeton University, after analyzing data from the EarthChem database, argue that what truly governs the process of continental crust formation is the fractional crystallization that occurs as deep-mantle melts ascend—rather than the remelting of already-formed crust. Meanwhile, Australian scientists, through geochemical analyses of zircon Lu-Hf isotopes in meteorites that fell to Earth during the early stages of the solar system’s formation, suggest that the earliest crust may have formed more than 4.5 billion years ago.

　　Based on their analysis of measurements from more than 13,000 rock samples collected from around the world, researchers at the University of Bristol believe that the Earth’s continental crust—on which human life depends—is steadily shrinking. At the current rate of decline, the continental crust could disappear within billions of years.

　　3. Seismic mechanisms and monitoring and prediction research have received significant attention.

　　In 2015, global research on the mechanisms of earthquake occurrence as well as earthquake monitoring and prediction once again became a hot topic. Scientists from the Swiss Federal Institute of Technology in Zurich, in their study on the recovery of fault stress in the seismic zone following the 2011 Great East Japan Earthquake, pointed out that large thrust earthquakes occur randomly, with no specific location, magnitude, or recurrence interval. Researchers from the University of California, San Diego, using data from the Global Seismological Network (GSN), found that the 2015 Nepal earthquake was caused by three distinct rupture segments: a weak rupture moving predominantly eastward, a rupture with maximum slip, and a relatively slow rupture. Geologists from the California Institute of Technology, leveraging GPS station data along with seismic station data and radar images from orbiting satellites, for the first time produced a comprehensive map of surface damage during the 2015 Gorkha earthquake in Nepal. Their study also indicated that the Himalayan region still faces a significant risk of future major earthquakes.

　　4. Major breakthroughs achieved in planetary science research

　　In July 2015, NASA announced the discovery of a “second Earth”—Kepler-452b—located in the habitable zone 1,400 light-years from Earth. This announcement sparked a global surge in interest among leading space-exploration nations to conduct Earth science research in interstellar space. In September of the same year, NASA reported evidence of liquid water on Mars. Using its ChemCam laser instrument, NASA’s Curiosity rover analyzed certain light-colored rocks on Mars and found that these rocks closely resemble Earth’s granitic continental crust. It can be said that this marks the first time humanity has detected what appears to be “continental crust” on Mars.

　　In addition, on July 14, 2015, at 7:49 a.m. EDT, the U.S. spacecraft New Horizons made a close flyby of Pluto, becoming the first human probe to explore this distant dwarf planet.

　　Trends in Resource Technology Development

　　1. The mechanisms behind the formation of mineral resources and related environmental issues in exploration and development have attracted considerable attention.

　　Scientists from the University of Bristol in the UK, by studying modern volcanic arcs—key copper-mining regions worldwide, including Chile—have developed a two-stage copper ore-forming model that explains how salt-rich fluids separate from large-scale magmatic bodies and concentrate copper to form economically viable deposits, thereby revealing the true link between copper mineralization and magmatism. Researchers from the University of Zurich in Switzerland, after studying the Witwatersrand Basin in South Africa, suggest that harsh Earth conditions characterized by volcanic rains, oxygen-poor rivers, and Archean-era organisms played a crucial role in the formation of these sedimentary gold-placer deposits.

　　The United States Geological Survey (USGS) has published a special issue in the international journal "Applied Geochemistry," which elaborates on the unique environmental impacts of mining—and the associated monitoring, prediction, and mitigation measures—from four key perspectives: mining prediction tools, pollution prevention during mining operations, mine wastewater treatment, and toxic substance monitoring.

　　2. Research on environmental risks and management issues related to the development of unconventional oil and gas resources is receiving increasing attention.

　　Governments of many countries attach great importance to the environmental issues arising from unconventional oil and gas development. For example, the Bureau of Land Management (BLM) under the U.S. Department of the Interior has released the final regulations on hydraulic fracturing; the German Chancellor’s Cabinet has signed a draft bill on hydraulic fracturing; and the United Kingdom has launched monitoring of hydraulic fracturing activities and initiated a pre-fracturing environmental baseline monitoring program.

　　Meanwhile, scientists are also highly enthusiastic about researching related environmental issues and corresponding remediation technologies. Researchers at the University of Colorado in the United States have developed a wastewater treatment technology based on microbial fuel cells, which can more conveniently remove salts and organic pollutants from wastewater generated during oil and gas extraction, thereby achieving effective treatment. Moreover, this technology can also generate additional electrical energy that can be used to power equipment or for other purposes, bringing new hope for low-cost treatment of wastewater produced during oil and gas operations.

　　Trends in the Development of Atmospheric and Oceanic Sciences

　　1. Progress has been made in the study of atmospheric composition mechanisms and their impact on climate.

　　Researchers from the United States, Switzerland, and South Korea have, through their studies, unveiled the mechanisms behind changes in atmospheric CO2 concentrations over the past millennium. They point out that, on timescales ranging from several decades to a century, the primary driver of fluctuations in CO2 concentration is the feedback loop between climate and terrestrial carbon reservoirs. Researchers at the University of Michigan in the United States used a global climate model to quantitatively analyze the impact of changes in atmospheric oxygen levels on climate. They found that throughout Earth’s history, variations in atmospheric oxygen levels have significantly influenced global climate patterns: a decline in oxygen levels would lead to lower atmospheric density, faster surface evaporation, and subsequently increased precipitation and warmer temperatures. Researchers at the Potsdam Institute for Climate Impact Research in Germany argue that oceans play a crucial role in the long-term effects of atmospheric decarbonization. They note that due to the inertia of ocean systems in responding to CO2 and heat, even if atmospheric decarbonization efforts were implemented today at the current emission rates, their effectiveness would likely be limited.

　　2. New insights gained in the study of factors influencing climate prediction

　　In 2015, scientists from the Helmholtz Centre for Ocean Research in Germany first demonstrated a phase-synchronized relationship between the 11-year cycle of solar activity and the North Atlantic Oscillation (NAO), thereby elucidating the mechanisms underlying the transmission of surface climate signals and the interactions between the Earth and the atmosphere. This discovery offers a new perspective for improving the accuracy of long-term climate predictions. Researchers at the Potsdam Institute for Climate Impact Research (PIK) in Germany, drawing on causal-effect theory, have developed a method based on dimensionality reduction and causal-relation reconstruction. This method can be used to assess the global impacts of geoengineering and extreme events, enhancing our understanding of the resilience of complex systems to extreme events.

　　In addition, researchers at Stanford University in the United States, through quantitative analysis of the impact of atmospheric circulation changes on extreme temperature events, pointed out that changes in mid-latitude atmospheric circulation can partially explain the variations in extreme temperature events in the Northern Hemisphere. Both thermodynamic and dynamic factors contribute to the trends in extreme temperature changes.

　　3. New priority directions and key areas for atmospheric science research have been proposed.

　　In March 2015, the Scientific Steering Committee of the International Ocean-Atmosphere Research Program (SOLAS) released a newly revised draft strategic plan for the next 10 years (2015–2025), outlining that SOLAS will in the future focus its research on five core themes: greenhouse gases and the ocean, the air-sea interface and its fluxes of matter and energy, atmospheric deposition and marine biogeochemistry, the interconnections among aerosols, clouds, and ecosystems, and the role of marine biogeochemical processes in regulating atmospheric chemical processes.

　　From May 25 to June 12 of the same year, the 17th World Meteorological Congress of the World Meteorological Organization (WMO) adopted the WMO’s future strategic plan, identifying seven priority research areas for the period 2016–2019: disaster risk reduction; the Global Framework for Climate Services; the WMO Integrated Global Observing System; aviation meteorological services; polar and high-altitude regions; expansion of meteorological and hydrological capacities; and WMO organizational governance.

　　4. Deep-sea research and the exploration and utilization of deep-sea resources are receiving attention.

　　In July 2015, the British Geological Survey (BGS) announced a new collaboration on deep-sea geological surveys to advance deep-sea research. Also in that month, the journal Science published an article titled “Managing Deep-Sea Seabed Mining,” noting that the International Seabed Authority (ISA) is currently reviewing the regulatory framework for deep-sea seabed mining. Researchers from leading global institutions will collaborate to develop strategies that strike a balance between the commercial extraction of deep-sea resources and the protection of marine biodiversity. In September, the European Marine Board (EMB) released a report entitled “Drilling Deeper: Key Challenges for 21st-Century Deep-Sea Research.” The working group reviewed the current state of deep-sea research, identified existing knowledge gaps, and outlined some of the future needs for the exploration and management of deep-sea resources. The report proposed goals for future deep-sea research along with related key areas of action, and recommended integrating these goals and action areas into a coherent whole. It emphasized that the foundation of a comprehensive European framework lies in supporting the development of deep-sea activities and underpinning the growth of the blue economy.

　　5. Research on the Arctic and its development strategies is receiving increasing attention.

　　The Arctic region, with its immense economic value, strategically important military location, significant impact on the global trade landscape, and tremendous scientific research potential, is increasingly becoming a focal point of attention for countries around the world, sparking competition among them.

　　In June 2015, the Center for Strategic and International Studies (CSIS) in the United States released a strategic research report titled “The United States in the Arctic,” outlining emerging trends in U.S. Arctic strategy. The report also pointed out that the United States is currently facing significant changes and challenges in the Arctic and urgently needs to enhance its operational capabilities in the region. CSIS further published a report titled “The New Ice Curtain—Russia’s Arctic Strategy Study,” which analyzes Russia’s future multilateral cooperation in the Arctic and its impact on the increasingly fragile Arctic ecosystem. As commercial shipping traffic in the Arctic continues to rise, the National Oceanic and Atmospheric Administration (NOAA) of the United States has stepped up efforts to update nautical charts for the region. In 2015, the Office of Coast Survey under NOAA used data collected by its own vessels as well as by the Coast Guard to update Arctic navigation charts, covering a total distance of 12,000 nautical miles.

　　Research infrastructure construction

　　1. Deployment of Earth observation and monitoring facilities has been strengthened.

　　In January 2015, the U.S. National Oceanic and Atmospheric Administration launched the Deep Space Climate Observatory (DSCOVR) satellite, which will provide more reliable early warnings of solar storms and enhance our ability to monitor solar activity. The UK Met Office announced that it will complete this year the construction of a comprehensive atmospheric monitoring network—known as the “Light Detection and Ranging systems” (LiDARs)—specifically designed to detect and forecast the distribution of volcanic ash. The entire monitoring network consists of 10 LiDAR detection units, ultimately enabling the acquisition of detailed information on the characteristics and vertical distribution of atmospheric particulates.

　　2. Crowdsourcing technology is being applied in disaster early warning.

　　The crowdsourced earthquake early warning system, jointly developed by the U.S. Geological Survey (USGS), the California Institute of Technology (Caltech), NASA’s Jet Propulsion Laboratory, and other institutions, has been widely adopted on smartphones and similar devices. Leveraging GPS sensors equipped in smartphones and other such devices, this system provides early warnings for major earthquakes. Furthermore, a crowdsourced earthquake early warning simulation was conducted using real data from the 2011 Tohoku earthquake in Japan, which had a magnitude of 9.0.

　　Meanwhile, the University of Leicester in the UK announced its participation in the EU’s IMPROVER project, which also focuses on leveraging social media to build disaster early-warning systems. The university stated that it will use social media platforms to enhance communities’ capacity to respond to both natural and man-made disasters.