The earth breathed fire.

On a stormy night in December 1943, Masao Mimatsu felt a jolt. His house shook. An earthquake! He looked through the swirling snow to Mount Usu, less than two miles away. Mount Usu was a volcano, but it had been quiet for 33 years. Was it going to erupt again?

Masao was a postmaster in the village of Sobetsu in northern Japan. He had lived his whole life at the foot of Mount Usu. As a boy, he had often climbed the mountain. In the summer of 1910. when he was 23 years old, Mount Usu had erupted. It had blasted smoke, ash, and rocks into the sky. Seeing that eruption, Masao developed an interest in volcanoes, which became a lifelong hobby.

In 1943, Japan was fighting in World War II, a terrible conflict that caused suffering for people all over the world. Masao knew that the people living near Mount Usu were enduring great hardships due to the war. An eruption would make it even harder to survive.

Earthquakes continued through New Year's Day. There were no scientists to monitor the volcano. They were all busy with the war. Masao was also busy, making sure the mail was delivered, but he found time to observe the volcano every day. He kept a diary of all earthquake activity. On January 1, 1944, he wrote, "Two earthquakes strong enough to knock things off of shelves."

Masao Climbs a Volcano

Masao climbed Mount Usu to check for volcanic activity. The volcano remained quiet, but a mile to the east there were ominous signs. In the farming village of Fukaba, huge cracks appeared across roads. Water pipes broke. Railroad tracks were twisted by the shifting earth. The most troubling change was the ground itself. It was slowly rising, like the surface of an inflating balloon.

All winter the earthquakes continued. In spring, the farmers of Fukaba returned to their fields, despite the rumbling in the earth below. On the morning of June 23, 1944, a farmer spotted white smoke coming out of the ground. Suddenly he heard an enormous explosion. He raced back to the village as the earth erupted, blasting ash and large rocks into the sky. By midday, the green fields and forests were covered with almost a foot of volcanic ash for a mile in all directions.

Masao rushed to the site. The explosions had created a crater 150 feet across and 100 feet deep. A new volcano had been born. "The crater was in the same place that I sat and ate my lunch yesterday," he wrote.

During the next four months, earthquakes and eruptions continued to rock the land. "Ash clinging to the plants caused the crops to die," Masao reported. "The local farmers are in despair."

The Villagers Flee

The people of Fukaba fled their homes. Soon, their houses were pounded to fragments by rocks blasted like cannonballs out of the new volcano. Masao wrote that the volcano "looked like a monster breathing out fire." But the danger did not stop him. As the volcano pushed skyward, he climbed up its jagged slopes to make observations, and he kept a careful record of its growth.

Molten rock, called lava, started forcing its way out of the crater. This lava hardened into a black dome, shrouded in white smoke. For the next eight months the lava dome continued to push upward until the volcano stood 1,300 feet high.

As the volcano grew, the war continued, causing great hardship for the people. Finally, on August 15, 1945, after years of war, the emperor of Japan made a radio address to his people: Japan had surrendered. The war was over. Six weeks later, Masao recorded that the new volcano was quiet at last. He noted that "signs of joy could be seen on the faces of the totally exhausted people."

Masao named the volcano Showa Shinzan. Showa honors the emperor of Japan at that time. Shinzan means "new mountain" in Japanese.

Masao Saves the Mountain

Many people wanted to dig mines into the volcano to get sulfur and other minerals that had come to the surface during the eruptions.

To save the mountain, Masao sold some of his own property and used the money to buy Showa Shinzan from the Fukaba farmers. He protected Showa Shinzan for the rest of his life. Today it is protected by the government of Japan.

Masao was a postmaster, not a scientist. But his careful notes, photographs, and sketches were an important contribution to the understanding of volcanoes. In 1958, his report on Showa Shinzan was presented at an international conference on volcanoes, and he was recognized for his contribution.

Showa Shinzan has not erupted for more than fifty years. You can visit it. It is a rusty-red, rocky mountain standing where farmers once grew wheat. The volcano is quiet, but steam and smoke still escape from its jagged sides. At its base is a statue of postmaster Masao Mimatsu looking up at the volcano whose birth he recorded.