It has been described that in order to understand the changing history of the earth for millions of years, human beings must read three "books": one is the history of deep-sea sediments, the other is the history of polar ice cores, and the third is the history of loess. Liu Dongsheng is a person who has made outstanding contributions to the study of the history of loess formation and evolution.
"Yellow land is the place where we rest for generations. It is a huge geological literature library, which contains all kinds of information about the changes of the earth's environment. It is like a key that can solve countless mysteries. " Loess, in the eyes of ordinary people, may only see sandstorms or poverty, but after nearly 60 years of "close contact", Liu Dongsheng has regarded it as a treasure of life.
This can be seen from the story of why Liu Dongsheng chose loess research: "After my work, I mainly engaged in vertebrate paleontology research, especially fish fossils research, which also attracted attention at home and abroad. In the early 1950s, Premier Zhou Enlai asked a Japanese journalist to talk about environmental issues, which left a very deep impression on me. Later, the Prime Minister proposed to pay attention to environmental issues. I turned from simple geological research to earth environmental research, and I started an indissoluble bond with loess. "
Hu Changkang, the wife who has lived with Liu Dongsheng for half a century, may be more authoritative: "He is honest and just wants to work and do more work. We used to live in Nanjing for seven or eight years, and we have never been to the surrounding attractions. "
"He regards loess as life." People who have come into contact with Liu Dongsheng often send out such feelings. His colleagues will never forget that in 1950s, Liu Dongsheng and others crossed the Loess Plateau from south to north and from east to west, and completed the 10 section, which was more than 1000 km long. They live and eat in the wild on foot. Liu Dongsheng led a team to drive from Beijing to the west for a field trip. He gets up at 6 o'clock every morning and calls a meeting at night to study the problem. During the inspection in Changbai Mountain, the weather was terrible. The students ran to the car after sketching, but after waiting for a long time, the teacher didn't come back. It turns out that he is still drawing and recording carefully. ...
"He is a super old man." Colleagues say this about Liu Dongsheng.
This "super" naturally includes the "dazzling aura" hanging over Liu Dongsheng's head: 1942 graduated from Southwest Associated University of China Academy of Sciences, Third World Academy of Sciences, Eurasian Academy of Sciences, director of the Quaternary Research Committee of China, and chairman of the International Quaternary Federation. ...
Of course, "super" is far more than that. He has devoted himself to loess research for 60 years and has never stopped his field trip. When he was 70 or 80 years old, he still personally visited the South Pole, the North Pole and the Qinghai-Tibet Plateau.
"There will be setbacks in any scientific research, and loess research is no exception, but Mr. Liu's persistent scientific pursuit and solid style of study left a deep impression on us, and his achievements are inseparable from this persistent spirit." Student Guo and his colleague Liu Dongsheng said.
It is this persistence that has made Liu Dongsheng's world-renowned achievements and opened the sacred book of the earth's climate-loess.
▲ "I can't overestimate the respect his research has gained in international academic circles."
"He enjoys a high reputation and is deeply respected internationally", "I can't overestimate the respect his research has gained in international academic circles". Is it appropriate for international peers to evaluate Liu Dongsheng in this way? When people understand his achievements, they have their own conclusions.
Since 1804, there have been two theories about the origin of loess in the world-"wind theory" and "water theory". Since 1950s, Liu Dongsheng has conducted a lot of field investigation and experimental analysis on the Loess Plateau, completed many monographs such as Loess in the Middle Reaches of the Yellow River and Loess Accumulation in China, and put forward an important breakthrough in the theory of "fresh air formation", which expanded the aeolian deposition from the loess layer at the top of the Loess Plateau to the whole loess sequence, and extended the aeolian deposition that only emphasized the handling process in the past to the whole process of material source-handling-deposition-deposition. This quelled the theory of "wind-driven" and "water-driven" and laid the foundation for the study of global change.
The four ice ages theory put forward by foreign scholars from 65438 to 0909 dominated the paleoclimate research in the first half of the 20th century. From 65438 to 0958, according to the multicycle characteristics of loess and paleosol, Liu Dongsheng found that the Quaternary climate alternated between cold and warm for more than four times, which challenged the classical four ice ages theory, and finally established the multicycle theory of environmental change, which became a major turning point in the study of global environmental change.
In 1980s, Liu Dongsheng reconstructed the history of climate change for 2.5 million years on the basis of China loess, making China loess the most important record file of paleoclimate change, becoming the three pillars of global environmental change research together with deep-sea sediments and polar ice cores, making important contributions to global climate change research and being convinced by the international scientific community.
From 65438 to 0964, Liu Dongsheng has been devoted to the study of the uplift of the Qinghai-Tibet Plateau and the environmental evolution in East Asia, combining the study of the Qinghai-Tibet Plateau with the study of the Loess Plateau, and combining the evolution of the solid lithosphere with the evolution of the earth's surface sphere, opening up a new field of earth science. Since the 1990s, the interaction between the layers of the earth system has become a research hotspot in international academic circles.
"The list of these achievements may be a bit monotonous, but it is enough to make people respect." Liu Dongsheng's colleague said. Liu Dongsheng's theoretical contribution in the field of earth environmental science research has been recognized by international academic circles, and his published articles have been cited by the internationally renowned retrieval system SCI for more than 3000 times. In 2002, he won the Taylor Prize, the highest international environmental science achievement award, which was awarded to scientists who have made great contributions to discovering and solving global environmental problems.
▲ "Loess is closely related to human life. A few more generations can't fully understand. "
Is it too far away from today to deal with loess all my life and study the ancient environment millions of years ago?
"In fact, Liu Dongsheng's research results have been closely related to the natural environment and human life. The evolution process and periodicity of temperature, humidity, hydrology and vegetation in the ancient environment are of great significance for understanding the environment and climate today and in the future. " Researcher Ding Zhongli, director of the Institute of Geology and Geophysics of China Academy of Sciences, said, "For example, in recent years, sandstorms have occurred frequently in China. Apart from man-made destruction of ground vegetation, is it related to the periodic dry climate evolution in nature? This requires a large-span natural historical evolution and its laws as the research background. "
"Studying the past is only for the future, otherwise the research will lose its direction." Liu Dongsheng believes that the more we go back to the past, the more difficult it is to understand the book Loess in China. Loess can't be fully understood by several generations.
It is in order to study the loess closely related to human life that Liu Dongsheng attaches great importance to the cultivation of talents and team spirit, just as he was evaluated when he won the Taylor Prize: "Dr. Liu Dongsheng not only made outstanding contributions in many basic scientific fields, but also made great contributions in inspiring and cultivating the younger generation of scientists in China."
Over the past 50 years, Liu Dongsheng has set an example and trained a large number of scientific research talents, and now it has become the backbone of the scientific research front. Since 1982, he has been teaching in the Graduate School of China Academy of Sciences, and is still guiding graduate students' field investigation and indoor research.
Several generations of loess researchers in China and the loess age they studied showed an interesting sequence: Liu Dongsheng established the most complete 2.5 million-year continental paleoclimate record based on loess; Since then, Liu Dongsheng student Ding Zhongli and others have pushed it to 6 million to 8 million years ago; The history of the younger generation of Guo and others can be traced back to 22 million years ago.
"For geology, the supplement of new talents is very important. Exploring the unknown mysteries of the earth is very attractive and requires more young people to participate in the research. " Liu Dongsheng appealed to young people.