Earth and Jupiter are the only two planets in the solar system that still have volcanic activity today. Volcanic activity is frequent on Earth, while it occurs sporadically on Jupiter, mostly on its moon Io. Judging by volcanic activity, Earth is the youngest of the eight planets. Although it is nearly 4.6 billion years old, it is still young compared to the universe, which is over 10 billion years old. There are no fewer than 1,343 active volcanoes on Earth. Since the year 2000 alone, there have been more than 5,000 recorded independent volcanic eruptions, and in recent decades, there have been more than 50 eruptions each year. These volcanic eruptions not only occur on land, but also in the ocean. Even at depths of 3,000–4,000 meters, where the pressure reaches 30–40 megapascals, volcanic eruptions can still occur. The ocean floor, which covers two-thirds of the Earth's surface, is almost entirely composed of basalt formed after volcanic eruptions. Many islands in the ocean are formed by volcanoes emerging from the water, such as the Hawaiian Islands in the Pacific Ocean, Easter Island, the islands of Mauritius and Reunion in the Indian Ocean, and São Tomé and Príncipe in the Atlantic Ocean. Easter Island is a volcano that has emerged from the water.
The "fire chain" along the Pacific Rim: Volcanoes are not evenly distributed globally. Two-thirds of them are concentrated along the "fire chain" along the Pacific Rim. This fire chain stretches from Indonesia, the Philippines, and Japan in the western Pacific Ocean to Sakhalin Island and the Kamchatka Peninsula in northeastern Asia, then connects to Alaska via the Aleutian Islands in the east, and along the Rocky Mountains, Cascade Mountains, and Andes Mountains on the west coasts of North, Central, and South America, extending south to the South Shetland Islands in Antarctica. There are also volcanic activities in East Africa (the East African Rift Valley), along the Mediterranean coast, and in Iceland in the Arctic Ocean. Countries with many active volcanoes include Indonesia, Japan, the United States, Ecuador, and Iceld.
Indonesia, located between the Pacific and Indian Oceans, is a country with thousands of islands and the most active volcanoes in the world, with 129 active volcanoes. The Tambora volcano on Sumbawa Island in northern Indonesia had a major eruption in 1815 that lasted more than three months. It was the largest volcanic eruption in recorded history, with 70 billion tons of erupted material, 99% of which were gases and volcanic ash. The volcanic ash filled the sky, making it dark for three days in a 480-kilometer radius, and 92,000 people lost their lives in this volcanic eruption. Krakatau volcano is another famous volcano. Its violent eruption on August 27, 1883, had the effect of "thunder heard ten thousand miles away and ash scattered across three oceans". It destroyed the volcanic island and formed a huge volcanic crater 250 meters deep and 7 kilometers in diameter, which is still uninhabited today.
South America is a very active volcanic region, with most of the world's volcanoes above 5,000 meters located there, such as the Popocatépetl volcano in Mexico, the Ruiz volcano in Colombia, and the Cotopaxi volcano in Ecuador. The highest mountain in South America, Aconcagua, is located in Argentina and is an extinct volcano.
Volcanoes in Africa are mainly distributed along the East African Rift Valley. Mount Kilimanjaro, located on the border of Tanzania and Kenya, is the highest mountain in Africa, with a peak elevation of 5,895 meters and is also a volcano.
Volcanoes in Europe are mainly distributed along the Mediterranean coast and related islands. Mount Etna, located in the northeast corner of Sicily, is the highest active volcano in Europe and one of the very few active volcanoes that have never stopped erupting since its first eruption in 475 BC. In 1169, a volcanic eruption destroyed the city of Catania. Iceland, located in the Arctic Ocean, although three-quarters of the island is covered by modern glaciers, there are hundreds of volcanoes distributed over 13,000 square kilometers, making it one of the countries with the highest volcanic density and abundant geothermal resources.
In South America, the Andes Mountains are the most active volcanic region. Most of the world's volcanoes above 5,000 meters are located there, such as the Popocatépetl volcano in Mexico, the Ruiz volcano in Colombia, and the Cotopaxi volcano in Ecuador. The highest mountain in South America, Aconcagua, is located in Argentina and is an extinct volcano.There are also many volcanoes in the oceans. For example, New Zealand and Fiji are island countries with volcanoes. Although Antarctica is a land of ice and snow, there are modern volcanic eruptions on Ross Island and Deception Island. It can be seen that volcanoes are distributed everywhere, whether on land or in the oceans, and whether in the tropics or at the poles.