Earth Sciences

This article focuses on answering the question "Are there active volcanoes in China?" It points out that although China lacks modern volcanic eruptions, there are still more than 10 active volcanoes in the country. It lists the distribution of volcanoes in various regions of China and explains the evolution of volcanic activity in China since the Cenozoic Era and the reasons why modern volcanic activity is not active

This article focuses on the question "Where are volcanoes on Earth?" and introduces the basic situation of volcanic activity on Earth, explaining that volcanoes are not evenly distributed globally, but are mainly concentrated in the "fire chain" along the Pacific Ocean rim. At the same time, they are distributed across all continents, oceans, and polar regions. The article also lists a number of representative volcanoes and related eruption cases in various regions.

This article focuses on answering the question of "Can volcanic eruptions be observed up close?" It explains that whether volcanic eruptions can be observed up close depends on the form and scale of the eruption. It introduces two basic eruption forms: central and fissure, as well as the characteristics of typical eruption types such as Plinian and Hawaiian eruptions. At the same time, it explains the viewing value of volcanic eruptions and the related precautions for observing them up close.

The article "Why Do Volcanoes Erupt?" introduces the definitions of extinct volcanoes, active volcanoes, and dormant volcanoes; the different criteria for classifying active volcanoes; the differences in the cycle and frequency of volcanic activity; lists the eruption cases of Mount St. Helens and Mount Pinatubo; explains the geological causes of volcanic eruptions; and illustrates the relationship between volcanoes and earthquakes, pointing out that volcanic activity is a symbol of the Earth's vitality.

This article focuses on the question "Is a volcano an underground fire?" It introduces the English etymology of the word "volcano" and the naming origin in ancient Rome, lists the volcano-related records in multiple ancient Chinese documents, points out that in ancient China, the spontaneous combustion of underground coal, coal-gas or oil-gas reservoirs was often mistaken for volcanoes, explains the modern definition of volcanoes, and mentions that volcanic activity is a symbol of the Earth's vitality.

This article explores the question of "Can human activities trigger earthquakes?" It points out that from the perspective of energy and the depth of earthquake occurrence, it is extremely difficult for human activities to induce major earthquakes, but there is a possibility of triggering earthquakes. Taking reservoir-induced earthquakes as a typical case, the article introduces the definition of reservoir-induced earthquakes, related examples, the probability of occurrence, the maximum magnitude, and the triggering principle, etc.

This article focuses on the question of "why earthquakes are particularly frequent at times", introducing the cyclical pattern of earthquakes alternating between active and quiet periods, explaining that this cyclicality stems from the cyclical process of energy accumulation and release in underground rocks, and pointing out that the rapid spread of information on the internet and the occurrence of major earthquakes in densely populated areas can give people the illusion that earthquakes are more frequent

This article focuses on the question of why we can't feel some earthquakes, explains the reasons why humans can't perceive some earthquakes, and introduces the role of high-sensitivity seismographs and earthquake monitoring networks in earthquake monitoring and research on the internal structure of the Earth.

This article focuses on why seismographs can record earthquakes, introducing the historical significance and related historical events of the wind-sensitive seismograph invented by Zhang Heng in the Eastern Han Dynasty, the working process and technological advancements of modern seismographs, and explaining that seismographs play a role by recording the seismic waves generated by earthquakes. However, they cannot predict earthquakes and are an important tool for earthquake prediction research.

This article focuses on the core question of "why the earth trembles", reviews the development of human understanding of earthquakes, introduces various ancient theories about the causes of earthquakes, the elastic rebound theory and the causes of tectonic earthquakes, the global distribution pattern of earthquakes and its relationship with plate tectonics, as well as other types of earthquakes such as volcanic earthquakes.

The article "Why Is the Interior of the Earth So Hot?" introduces the topic with the example of a boiled egg, and then describes the temperature distribution at different depths within the Earth, the sources of high temperatures within the Earth, and the current status and relevant examples of geothermal energy development and utilization.

Focusing on the question of "where does the driving force of crustal movement come from?" the article introduces the process of earth scientists exploring the driving force of the evolution of the land-land pattern. They successively proposed the hypothesis of mantle convection and revised the cognition with the help of seismic wave detection, and finally clarified that the convection of the lithosphere plate in the lower part of the mantle. The drag down movement is the source of power for crustal movement and the evolution of the land-land pattern.