Important facts and information about Japan’s volcanoes

The origin of Japan’s volcanoes

Japan is a part of what is known as the Pacific Ring of Fire which is a group of seismically active countries that surround the Pacific Ocean. Because these countries are usually found wedged between tectonic plates, they are usually consisted of a countless number of volcanoes and are more prone to earthquakes.  Japan is actually one of the countries in the world with the most number of active volcanoes.

Most of Japan’s geology, both at its lowest and highest point, are made from volcanic material because of its high volcanic activity. Explorers, visitors, and scientists are sure to find rocks of volcanic origin atop most mountains in Japan. The benefit of this is that it produced beautiful landscapes for hiking and exploration and has also given rise to the popularity of hot springs, or onsen, in the county.

Based on a report from the Oregon State University, most of Japan’s land area today was under the sea at the time the continents were beginning to take its shape. It was only due to volcanic activity that the islands of Japan have been lifted to what we can see in present day.

Japan and their new technologies

Throughout Japan’s history, there had been chilling records of disasters and calamities caused by volcanic eruptions and explosions. There had been incidences of entire cities suffering from the consequences of living so near active volcanoes. Because of this Japan is the leader in disaster preparedness.

Japan has systems not only to monitor volcanic eruptions and explosions but to also take a close look at other consequences of volcanic activity like earthquakes and tsunamis. They have early warning systems and has even set up hundreds of sensors all over the country. Through time, they have also turned their structures into earthquake resistant and tsunami safe buildings.

Because of this, Japanese engineers and scientists have devised technologies that could help them forecast volcanic activity by translating data based on the behavior of a volcano. According to the Japan Meteorological Agency, they observe the times it releases smoke, the times it spews out plumes of ash to significant heights and also the periods that the area vibrates. These are common indicators for scientists to find out if a volcano is near its time of the eruption.

Furthermore, scientists from the Agency have developed means to measure volcanic eruptions’ return periods which is the length of time for which a volcano becomes ripe for an eruption. When volcanoes are overdue for an eruption, local authorities closely observe safety measures in surrounding areas.

Tips to remember for safety during volcanic eruptions

The Japanese government has made actions to improve their means to monitor volcanic activity to ensure the safety of its citizens. They have taken appropriate action to increase monitoring centers and to train more people to study the behavior of volcanoes.

They have also provided training and seminars for residents living near volcanoes so they would know what actions to take in the event that a volcanic eruption is expected. On top of this, they have also constantly relayed important information and details to local residents as well as tourists exploring volcanoes to enable them to know when to take the most appropriate action. What makes it more helpful is that disaster mitigation schemes have been set out to all regions of Japan, especially places as crowded as Tokyo.

Here are a few important reminders for anyone living or staying in the vicinity of volcanoes:

Before Eruption: When living kilometers away from a volcano, it is crucial to stay informed. Constantly look out for news that would give enough information or details regarding the volcano’s current state. During this time, it is also a good idea to ready evacuation packs which contain masks, goggles, clothing, water, and food enough for the family for a few days.

During Eruption: When a family is living in the danger zone, it is best to evacuate when the local authorities have given their prompt for evacuation. This is because lava whose temperatures can go as high as thousands of degrees celsius, is definitely fatal to anyone or anything it comes across. So be sure to carry out your town’s emergency and evacuation plans. Closely coordinate with authorities so they could bring the family to safety.

When living within the vicinity of the volcano but not in the danger zone, make sure to stay indoors as ash could bring about respiratory issues and other health hazards. Keep all the windows closed and the home well ventilated. Also, bring equipment, animals, and livestock to covered shelters.

After Eruption: Always listen to prompts if it is already safe to leave the house or if it is safe to return home. Make sure to wear long sleeved clothing, masks, and goggles before leaving your home. Also, it is expected that roofs of houses will be covered with ash which must be carefully swept away. However, make sure to wear appropriate protection while cleaning up the surroundings.

Japan’s active volcanoes: How many volcanoes are in Japan?

Most active volcanoes in Japan are formed from stratovolcanoes or complex volcanoes. These are more dangerous than others because they have the potential to produce violent eruptions, with lava whose temperatures are thousands of deg Celsius, that could wipe away nearby towns and villages. Stratovolcanoes are known for their ability to produce lahar which is a mixture of flowing liquefied ash and water. They also have the ability to produce volcanic bombs, an event that can randomly and excessively spew out plumes of ash at incredible heights (about hundreds of meters) vertically into the air.

Active volcanoes

In total, there are about 110 active volcanoes in Japan, a list of 47 are closely monitored by the government because of their potential for violent eruptions. This is especially important since many active volcanoes are surrounded by highly populated towns and villages. The Scientific American has reported that the 2011 Tohoku earthquake has made a significant list of volcanoes rumble and jittery sending some of them to their peak of activity.

Sakurajima is an active volcano located near the region of Kagoshima. Originally located on a small island, it has erupted so violently in 1914 that it turned the island into a peninsula and provided enough land to connect to the nearest city of Kyushu. This particular volcano, Sakurajima, is now at its peak of activity that it gives out hundreds of small eruptions and explosions in a year. And the fiery red glare of Sakurajima’s lava at night has turned Kagoshima into a tourist attraction. Tourists usually catch videos of its eruptions and millions around the world watch its terrifying beauty.

Mount Asama is considered as the most active volcano in the main islands and has been continuously erupting since 1982. It has been reported to erupt in the 1700s which have caused destruction on homes and livelihood that lead to a five-year-long famine in the area. It erupts so violently that it shoots out lava into the air sending structures at a distance on fire.

Mount Aso is considered as one of the largest volcanoes in the world because of its 120-kilometer circumference crater or caldera. It is one of the volcanoes made active by the 2011 Tohoku earthquake and has been known to erupt every few years. There are studies that show that there is a possibility for Mount Aso to create a volcanic eruption so large that it could bring catastrophes extending beyond the borders of Japan. Although there are no indications of this happening in the near future, there are studies that it has happened hundreds of thousands of years ago.

Japan Hell Valleys are locations in Japan which are made worse by the presence of active volcanoes. These are places which are usually made up of rocky terrains, hot steam vents, bubbling springs, and pools. They are usually barren and have a very strong smell of sulfur in the air. They are known as hell valleys because sulfur poisoning has caused deaths of small animals in the area. It is also considered as hell-like because of the plumes of hot, poisonous gases venting out of small holes in random locations. Although these Hell Valley views are spectacular, these places are cordoned off from visitors and are considered to cause serious health risks to visitors. Most people could only watch videos of Japan’s Hell Valleys from aerial shots.

Dormant volcanoes

On top of the active volcanoes, Japan also has a number of dormant volcanoes which have not erupted for a significant amount of time. They are considered dormant because they are presently inactive but there are great chances that they will erupt again. Normally, these dormant volcanoes (some of which are now considered as mountains) are now tourist spots because of their beautiful landscape and colorful forests.

Mount Fuji and its beautifully snow-capped crater or caldera have been an iconic spot in Japan which has attracted thousands of tourists every year. Although a lot of people confuse Mount Fuji with a mountain, it used to be a very active volcano. It is the highest elevation or peak in the country, its iconic view and beauty have been considered an important symbol of dynamism to the daily lives of the people.

This particular volcano’s last eruption was in 1707 for which an 8.7 magnitude has preceded it 49 days before the massive eruption. The Tohoku Earthquake of 2011, whose epicenter is quite close to Tokyo, has given rise to the possibility that this particular volcano is ripe for another eruption. Although scientists can't say if it WILL erupt, there are indications that Mount Fuji is already in its critical state.

Most famous volcanoes erupting in Japan’s history

The deadly eruption of Mount Unzen in the Kyushu Prefecture in 1792 is considered as Japan’s worst volcanic disaster in history. The death toll went up to about 15,000 people.The eruption was just the beginning and lava was the least of their problem.

The activity of Mount Unzen of Kyushu has caused a landslide of a 4,000-year-old lava dome which released a significant amount of pyroclastic material down to low-lying areas. The mass of soil and rock has reached the nearby sea causing wave surges and tsunamis in surrounding cities and regions. Up until today, the scars of the landslide can still be seen in the area.

There had been reports in late 2016 that the largest volcano in Japan is forecasted to produce a large eruption in the coming years. Signs of this dreaded eruption of Mount Aso could be seen through the last few months of the year 2016. Due to its large crater or caldera, groups in Japan are alarmed on what kind of damage it could cause to surrounding towns and villages.

The volcano has sent massive amounts of material to an unbelievable height covering towns with ash. Ever since, there had been warnings to locals and tourists to stay away from the said volcano. No one knows if it will erupt again and what extent the damage could be.

Present day active volcanoes in Japan and its global consequences

The Pacific Ring of Fire is a group of volcanically active countries that surround the Pacific Ocean. Although scientists believe that volcanoes in these areas are caused by movement of the tectonic plates, there are no evidence to prove that they are all interconnected.

Recent volcanic activities around the world are not necessarily related to each other. The different views of the scientists explain that data of eruption from one country in the Pacific Ring of Fire will not be enough to forecast if there will be another volcanic eruption somewhere else.

Although volcanoes in Japan could be active and violent. People from other parts of the Pacific Ring of Fire (much else other parts of the world) should not be too alarmed. For instance, a volcanic eruption in Japan will not create any significant effect on North America. However, there are possibilities of small waves from tsunamis that could reach islands in the Pacific but will not cause any deadly disasters.