Great Kantō Earthquake
The Great Kantō Earthquake was a megathrust earthquake that struck the Kantō Plain on the main Japanese island of Honshu at 11:58:32 JST on Saturday, 1 September 1923. It had an approximate magnitude of 8.0 on the moment magnitude scale, with its epicenter located some southwest of the capital Tokyo. The earthquake devastated Tokyo, the port city of Yokohama, and surrounding prefectures of Kanagawa, Chiba, and Shizuoka, and caused widespread damage throughout the Kantō region.
The event was a complex disaster, with modern research indicating it consisted of three consecutive shocks in the span of several minutes. The initial megathrust event in Kanagawa Prefecture was followed three minutes later by a magnitude 7.2 earthquake centered beneath Tokyo Bay, and two minutes after that by a magnitude 7.3 shock in Yamanashi Prefecture. Fires, exacerbated by strong winds from a nearby typhoon, spread rapidly through the densely populated urban areas, accounting for the majority of the devastation and casualties. The death toll is estimated to have been between 105,000 and 140,000 people, including tens of thousands who went missing and were presumed dead. Over half of Tokyo and nearly all of Yokohama were destroyed, leaving approximately 2.5 million people homeless. The disaster triggered widespread social unrest, including the Kantō Massacre, in which ethnic Koreans and others mistaken for them were murdered by vigilante groups based on false rumors.
In the aftermath, the Japanese government declared martial law and undertook extensive relief and restoration efforts. The earthquake prompted ambitious plans for the reconstruction of Tokyo, aiming to create a modern, resilient imperial capital under the leadership of Home Minister Gotō Shinpei. However, these plans were often met with political contestation, financial constraints, and local resistance, leading to a reconstruction that, while significantly improving infrastructure, fell short of the grandest visions. The disaster also fueled debates about national identity, modernity, and societal values, with many commentators interpreting the event as a divine punishment for perceived moral decline and advocating for spiritual and social regeneration.
The Great Kantō Earthquake remains a pivotal event in modern Japanese history, profoundly impacting urban planning, disaster preparedness, and social consciousness. 1 September is commemorated annually in Japan as Disaster Prevention Day.
Earthquake and immediate impact
The Kantō region of eastern Japan is prone to major earthquakes due to its location near complex tectonic plate boundaries. The 1923 earthquake occurred when the Philippine Sea Plate subducted beneath the Okhotsk Plate along the Sagami Trough. The initial shock, occurring at 11:58:32 JST on 1 September 1923, was a complex event. Modern analysis indicates a dual rupture on a broad trench-type fault: the first rupture occurred near Odawara in Kanagawa Prefecture, some southwest of Tokyo, followed about ten seconds later by a second shock on the other side of Sagami Bay near the Miura Peninsula. This was followed minutes later by two major aftershocks: a magnitude 7.2 earthquake beneath northern Tokyo Bay at 12:01, and a magnitude 7.3 earthquake in Yamanashi Prefecture at 12:03. Survivor accounts consistently describe these three distinct seismic events.The earthquake immediately toppled structures, crushed people, and caused widespread panic. Survivor accounts describe an initial period of stunned silence followed by a frantic rush as people tried to reunite with family and salvage belongings. Engineer Mononobe Nagao recalled the earth shaking "back and forth for what seemed like 15 seconds", followed by violent vertical convulsions that knocked people to the ground. Writer Tanaka Kōtarō described the sound as akin to a giant "blackening whirlwind" churning up the earth from "deep underground".
Fires and pandemonium
Within thirty minutes of the first tremor, more than 130 major fires broke out across Tokyo, particularly in the densely populated eastern and northeastern sections. These fires were fueled by overturned charcoal braziers used for midday meals, leaking gas from ruptured lines, and flammable debris from collapsed wooden buildings. Strong winds, associated with a typhoon passing off the coast, fanned the flames, creating massive firestorms that swept through the city. The air temperature in some areas reached.The combination of ongoing aftershocks and rapidly spreading fires led to pandemonium. Millions of residents attempted to flee, often carrying their possessions, which clogged the already damaged streets and bridges. Kawatake Shigetoshi described being trapped in a "wave of people" in eastern Tokyo, unable to move as fires approached from multiple directions. Many sought refuge in open spaces, such as parks and the grounds surrounding the Imperial Palace, but these areas quickly became overcrowded. Waterways like the Sumida River also became congested with boats as people tried to escape by water, only to face sparks and burning debris falling from the sky. The disaster quickly overwhelmed Tokyo's infrastructure and its capacity for an orderly evacuation.
Damage and devastation
The Great Kantō Earthquake was one of the most destructive natural disasters of the 20th century. Roughly half of Tokyo and virtually all of Yokohama were transformed into "blackened, corpse-strewn wastelands". The earthquake and subsequent fires destroyed an estimated 397,119 homes in Tokyo Prefecture alone, leaving about 1.38 million people homeless in Tokyo City. Across the seven affected prefectures, a total of 2.5 million people were displaced.The physical destruction was immense. In addition to buildings, the earthquake buckled roads, collapsed bridges, twisted train tracks, snapped water and sewer pipes, and severed telegraph lines. Tokyo's main aqueduct from Wadabori collapsed in two places and required extensive repairs. The sea floor in Sagami Bay dropped by over at the epicenter, triggering tsunamis that inundated low-lying coastal communities.
Fires were the primary cause of destruction, accounting for 90 percent of the fatalities. In Tokyo, districts like Asakusa, Kanda, Nihonbashi, Kyōbashi, Honjo, and Fukagawa were largely incinerated. The Honjo Clothing Depot, a large open area where tens of thousands sought refuge, became a death trap when a massive firestorm engulfed it, killing an estimated 40,000 people in minutes. Survivor Koizumi Tomi described the site as "hell on earth", surrounded by "endless rows of bodies: red, inflamed bodies; black, swollen bodies; bodies partially buried under ash and smoldering remains".
Governmental administration was crippled. In Tokyo, 44 percent of the main buildings burned to the ground, including the police headquarters and the ministries of Home Affairs, Finance, Education, Communications, and Railways. The vast majority of police stations and municipal and ward offices crumbled or burned. Out of Tokyo's 196 primary schools, 117 were destroyed, along with numerous higher girls' schools, trade schools, colleges, and universities. Social welfare facilities, including public dining halls, cheap lodging homes, and crèches, were annihilated. Over 160 public and private hospitals in Tokyo were destroyed.
The economic impact was also severe. The disaster exacerbated the economic downturn of the early 1920s and contributed to a genuine banking crisis in 1927. Roughly 7,000 factories were destroyed, including major spinning, dyeing, and tool manufacturing plants. Financial institutions suffered heavily, with 121 of 138 bank head offices and 222 of 310 branch offices in Tokyo City consumed by fire or reduced to rubble. Insurance policies offered little relief, as most contained clauses exempting companies from earthquake-related damage; eventually, the government intervened to facilitate partial payouts. Reconstruction brought a new surge of imports and, under these combined pressures, an early return to the gold standard was impossible. The disaster also led to significant unemployment. In September 1923, the unemployment rate in the wards of Tokyo reached 45%. By 15 November, across Tokyo Prefecture, 178,887 people were registered as unemployed, with the commerce and industry sectors most affected.
File:Desolation of Nihonbashi and Kanda after Kanto Earthquake.jpg|thumb|Ruins of Nihonbashi and Kanda, as seen from the roof of Dai-ichi Sogo building in Kyōbashi|center|600px
Casualties
The human toll of the Great Kantō Earthquake was catastrophic. Early estimates put the death toll as high as 140,000, but modern research based on the 1923 Great Kantō Earthquake Disaster Report puts the total number of fatalities at 105,385. Of these, 91,781 deaths were attributed to fires, while 11,086 were due to being crushed by collapsing buildings. Other causes included drowning and landslides. Kanagawa Prefecture suffered 32,838 deaths, while Tokyo Prefecture had 70,387. An additional 13,275 people remained classified as missing twelve months after the earthquake.People died in numerous ways: crushed by collapsing buildings, trampled in panicked crowds, burned alive in the fires, or drowned in rivers and canals while attempting to escape the flames. Some victims suffocated as fires consumed oxygen, while others were boiled alive in ponds offering no protection from the intense heat. The smell of burning human flesh and decaying bodies permeated the air for weeks. Disposing of the dead became a major public health concern, leading to mass cremations, particularly at the Honjo Clothing Depot.