The eruption of a volcano thousands of miles away actually gave the northern hemisphere a chill in the summer

The unexpected appearance of the "fish chaser"

In the 12th year of Emperor Kangxi's reign (1673), fishermen in Longkou, Shandong Province, encountered a strange thing: a huge beast that had never been seen before frequently appeared in the offshore fishing grounds. Wherever the beast went, many fish that had never been distributed there appeared - black carp. The fishermen were terrified and determined that the beast must be the "fish-driving man" under the Dragon King. In order to thank it for the black carp fishing season and to pray that the "fish-driving man" would not sink their boats, local fishermen always brought wine and meat tributes to show their respect when they went out to sea for many years. Such devout worship made the beast a god in the hearts of the local people, and this adventure was solemnly included in the local county annals.

Modern readers can already guess that the monster that the Longkou fishermen saw was most likely a whale. In fact, in the county annals of Rizhao County, Shandong Province at the same time, not only were stories about this whale also recorded, but there were even more detailed details to trace - when it jumped out of the water, yellow spots on its belly could be vaguely seen. This can't help but remind people of the description of a certain whale in the literary masterpiece "Moby Dick" - because diatoms are easily attached to the folds of the abdomen, a certain whale may have yellow mustard-colored patches on its abdomen, so it is called "sulfur bottom" by Western whalers, and it is the largest animal in the world, the blue whale.

However, the irony is that before being killed to extinction by commercial whaling, China's blue whales actually only had one group migrating between western Japan and the southern East China Sea. It is almost impossible for them to frequently appear in Rizhao and Longkou, Shandong. The herring that accompanies the blue whales is even more incredible. Its true form is the Pacific herring that was originally distributed around the Liaodong Peninsula and the Korean Peninsula. This cold-water marine fish rarely swam in the Shandong Peninsula. However, in the coastal areas of the Shandong Peninsula during the Kangxi period, there was a record of explosive growth and bumper harvests of Pacific herrings year after year.

A year without a summer in the northern hemisphere

The strange phenomenon that occurred on the Shandong Peninsula was only a small part of the abnormal celestial phenomena in the 17th century. In fact, since the first year of this century, the world has felt the unusual "cruelness" of nature: in the summer of 1601, Jiangsu and Zhejiang in China, which should have been rainy, suddenly suffered heavy snow. In July, Hebei and Shanxi in North China suffered even more severe frosts. The crops in the fields were almost killed by frost, resulting in serious harvest failures and famine, and even the tragic phenomenon of cannibalism. In Venice, a water city in southern Europe, the freezing of 1602 completely disrupted the rhythm of life of the locals. In the records of the time, people wrote that this was probably the first time in history that Venetians had to measure their hometown by foot; in England, because the whole summer was very cold, people had to buy winter clothes to survive the summer, which made woolen merchants earn a lot of money. But the story that happened in Russia was not so easy. In 1601, the agricultural areas of Tsarist Russia also suffered a severe frost impact, which triggered a disaster that lasted for three years. The total population of Tsarist Russia lost 30%. The tragic natural disaster even aroused the ambitions of powerful neighbors. The Polish-Lithuanian Commonwealth took advantage of the situation and intended to annex Russia. It was precisely because of this dispute that the foreshadowing of the hundreds of years of conflict between Russia and Poland was laid.

People from all over the world have left different records of this climate fluctuation that lasted for more than half a century and affected almost the entire world. In China, we call it the "Little Ice Age of the Ming and Qing Dynasties" and in the North American colonies, it was called the "Year Without Summer". However, what they have in common is that in that era dominated by the agricultural economy, such a long period of climate fluctuation significantly affected social life, and people were helpless about it. In order to pray for good weather, the officials of the Imperial Observatory in the East could only anxiously observe the celestial phenomena, while in the churches in the West, prayers also continued every night.

Volcanic eruption thousands of miles away

History seems to have played a joke on us. These superstitious behaviors that have no practical use have been faithfully recorded, inadvertently leaving clues for us to find the answer. In 1600, in the distant South American country of Peru, local priests were facing a greater challenge: in February of that year, the Enaptina volcano in the south suddenly began to move. The rumbling noises and frequent earthquakes from the volcano quickly attracted attention. Local priests went to the volcano to hold ceremonies, hoping that the offerings they brought could calm the anger of the mountain god. However, on the evening of February 19, 1600, the volcano inevitably erupted. According to the description of local Spanish colonists, the explosion of the volcano was so loud that it could be clearly heard even hundreds of kilometers away. Thousands of volcanic debris mixed with huge rock fragments, like deadly shells, mercilessly swept through dozens of villages, almost destroying all the buildings and turning them into a scorched earth. Lava splashed and rolled towards the Pacific Ocean 120 kilometers away from the volcano. After the one-month eruption was completely over, the entire area had become a ruin. Fortunately, since the area around Enaputina volcano is sparsely populated, an eruption of this scale only caused 1,500 casualties.

Image source: Tuchong Creative

But no one expected that the destructive power of this volcano would be far less than this.

Just like the magnitude of earthquakes, the destructive power of volcanoes also has its own evaluation system - the Volcanic Explosivity Index (VEI). This index measures the intensity of volcanic activity based on the total volume of debris ejected by a volcanic eruption. Level 0 refers to small volcanic activities without explosive eruptions, and each increase of 1 level means that the intensity of the volcanic eruption has increased 10 times.

According to today's estimates, the eruption level of Peru's Mount Enaputina has reached level 6, and this level of volcanic eruptions is rare in the history of human civilization. A few years ago, the eruption of Indonesia's Mount Sinabung caused great panic, and my country also dispatched special planes to bring Chinese tourists stranded in Indonesia back to China. However, according to the VEI standard, this was only a level 2 eruption; in history, the eruption of Mount Vesuvius that buried the ancient city of Pompeii only reached VEI level 5. In comparison, we may have a more intuitive understanding of this eruption in Peru.

It is estimated that at least 5-10 cubic kilometers of lava and debris were ejected from Mount Enaputina. At the peak of the eruption, the towering smoke column even reached 37 kilometers, which is obviously far higher than the stratospheric altitude of about 10 kilometers. Due to the lack of up and down convection, volcanic ash can easily spread to a long distance after entering the stratosphere. For a violent eruption like Mount Enaputina, the volcanic ash it produces can almost spread all over the world - during scientific expeditions to the North and South Poles, we have found volcanic glass fragments that are obviously from this volcano.

The impact of these debris was most evident in the years after the eruption. When volcanic ash floated in the cold and humid atmosphere, it provided condensation nuclei for moisture in the air, and huge cumulonimbus clouds began to appear around the world. As the main source of heat on the surface, sunlight was blocked and reflected by the dense clouds, and a global cooling suddenly started.

Volcanic eruptions are rapid, but their effects fade very slowly. Some of the smaller debris may not even settle for decades. Not to mention the large amount of sulfur-containing gases that were ejected into the atmosphere along with the volcanic ash, which, through complex chemical reactions, formed tiny sulfuric acid droplets in the air. These dust and droplets are like a veil over the originally transparent atmosphere of the earth. Decades after most of the debris had been washed away by rain, the light transmittance of the atmosphere was still affected, so that in Iceland in the mid-17th century, the sun was still dim enough to barely cast a shadow.

The temperature changes brought about by this long-term low atmospheric light transmittance even caused the shift of ocean currents. The Kuroshio, which originally originated in the northeast of the Philippines, passed through the East my country Sea and finally turned to the east coast of Japan, gradually moved southward in the following decades. Under its influence, the water temperature of the Yellow Sea and Bohai Sea dropped, and the Pacific herring that originally lived in the northern part of the Bohai Sea also expanded its range of activities to the coast of the Shandong Peninsula, attracting the visit of blue whales.

The butterfly effect is a familiar term to science fans, but the story that happened in the 17th century is beyond our imagination. A volcanic eruption in South America can affect the climate in Asia and even almost rewrite the fate of a European power. This may remind us that the structure and operation mechanism of the blue planet we regard as our home is more sophisticated and complex than any machine, and the mysteries it contains are worth our constant exploration.

The article is produced by Science Popularization China-Starry Sky Project (Creation and Cultivation). Please indicate the source when reprinting.

Author: Wandering science writer

Reviewer: Zhang Yuxiu, Associate Professor of Geology, School of Earth and Planetary Sciences, Chinese Academy of Sciences