CHAPTER 1941

North American Shelf, Oceanographic Research

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Special purpose ship Sōya (as of 1941)

- Displacement: 3.800 tons

- Speed: 12,1 knots

- Range: 5.000 nautical miles (9.260 km)

Nemuro to Vancouver: approx. 6.600 km

- ほうこうおんち

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At the end of February 1941, the Japanese Navy's special purpose ship Sōya departed from Yokosuka. This vessel was originally built as an icebreaking cargo ship intended for delivery to the Soviet Union. However, given the international situation just before the outbreak of World War II, the handover was never completed. Equipped with a state-of-the-art British-made sonar, the ship was acquired and retrofitted by the navy. She was assigned to carry out surveying, meteorological, and oceanographic observation missions. Last year, the Sōya had been dispatched to Saipan in the South Seas, where she conducted observations as part of advanced training. Even then, the ship had been engaged in monitoring atmospheric changes in the region.

The Japanese government initially showed little enthusiasm toward a British proposal. Prime Minister Konoe himself was indifferent to scientific initiatives. However, the British leadership's swift decision-making seemed almost abnormal. The situation was ultimately overturned by the navy.

The Japanese Navy had long prepared its fleet with the United States as the hypothetical enemy. However, the disappearance of the United States left them in a quandary. Although remnants of the American fleet remained in Hawaii, these forces lacked strategic coordination, making them essentially irrelevant. Without a national framework, even a large fleet is little more than a band of pirates; fleets gain their significance only when their actions align with national strategy.

Anyway. The navy pivoted to make Britain its next hypothetical adversary. Maintaining a massive fleet required an equally formidable enemy. For the sake of organizational survival—despite neither the intention nor significant benefits of actually waging war—plans for conflict with Britain were formulated. Yet, the lack of information about the conditions of the area midway between the North Pacific and North Atlantic, in other words, the area where North America used to be, presented a challenge. If, for example, the area was riddled with shallow reefs impassable to deep-draft warships, neither side could effectively conduct operations there. In such a case, battles would likely be confined to regions from Southeast Asia to India. Conversely, if the area was navigable, Japan would need to maintain the same level of vigilance in the Pacific as it had against the United States. Either way, intelligence was urgently required.

Meanwhile, Takashi Uda from the Ministry of Agriculture and Forestry also pressed for an investigation through his superiors. During his tenure at the Fisheries Training Institute of the Ministry, Uda had planned and led a comprehensive marine survey of the North Pacific near Japan, personally participating in observations. His concerns extended beyond fisheries resources—he argued for understanding broader oceanic changes, not for academic curiosity but for Japan's national interests. As a disciple of renowned geophysicist Torahiko Terada, Uda advocated for a holistic approach, including meteorology and tides, to assess the impacts of North America's disappearance on Japan's future.

His superior, Morisaburō Tauchi, a scholar involved in founding the Japanese Society of Fisheries Science, also stressed the necessity of investigating the North American waters.

These appeals had been ongoing since the previous year. With the British proposal for a joint survey in hand, these institutions lobbied persistently against the government's hesitance. Lacking firm convictions, Prime Minister Konoe eventually relented, saying, "If you insist that much, then fine." Following his approval, personnel were quickly selected, and the necessary equipment was procured at an accelerated pace.

The Navy possesses a dedicated survey ship named Chikushi. However, having just been launched in November of the previous year, she was not yet operational. A warship undergoes outfitting and thorough training before it enters service. Thus, another vessel—either a navy ship or a requisitioned civilian vessel—had to be used.

The Sōya, which had a proven record of observation work in Saipan, was chosen. Her existing equipment could be utilized as-is, and her origins as a cargo ship with significant load capacity made her an ideal choice. Aboard the Sōya were members of the Navy Hydrographic Department, the Ministry of Agriculture and Forestry's Fisheries Bureau, the Ministry of Education's Meteorological Bureau, and oceanographers from the University of Tokyo. Rear Admiral Masami Kobayashi was named the leader of the mission, with Takashi Uda as the head of the research team.

The Navy planned to dispatch a second wave, consisting of the Sixth Fleet's submarine tender fleet, once preparations were complete. They intended to study the navigability of submarines in the region as well. As a result, Rear Admiral Kobayashi would take command of a large fleet, including the submarine tenders he had previously been affiliated with.

The Sōya first set course for the area where Vancouver once existed.

"This was once off the coast of America... wasn't it?"

In March, when the ship reached the target area, Uda murmured in disbelief. There was nothing there. It looked no different from the open ocean they had been sailing through the previous day. Unbelievable as it seemed, celestial navigation confirmed that they were three nautical miles off the former location of Vancouver Island.

"Let's begin surveying."

Using sonar equipment, traditional rope-based depth measurements, and even diver-assisted investigations, the team began their work.

The North American continent had been immense. Progressing through the vast expanse left behind was slow, and the area that could be surveyed was limited. Britain's request for a joint survey was likely due to this very challenge. Navigational routes are often considered military secrets; having exclusive knowledge of such routes can provide a tactical advantage. However, the vastness of this new oceanic expanse was overwhelming. Collaborating with former enemies seemed like the only viable option. In fact, for its surveys of the Atlantic side, Britain had sought cooperation not only from Germany and Vichy France but also from neutral nations such as Spain and Sweden. Ending one war had made such joint efforts possible.

The Soviet Union, however, was notably absent. Germany had vehemently opposed its involvement, and Britain, eager to advance the surveys, had acquiesced.

After about a month of surveying, a curious pattern emerged.

"The depth is consistently about 45 meters wherever we measure. There are tidal fluctuations, of course, but the variation stays within 45,5 meters. That's roughly 25 fathoms."

"Considering the approximate area of the continent and the volume that disappeared, the influx of seawater would have caused the sea level to drop. From the extent of this drop, we estimated that the North American landmass submerged under the sea was between 40 and 50 meters in thickness. However, there would be uneven terrain with deep and shallow areas. Navigating the shallower areas would have been a problem. But no matter where we measure, we only get readings around 45,5 meters. Is the seabed completely flat?"

"If a landmass of this scale vanished, it would have caused massive earthquakes and tsunamis. While the impact was indeed significant, it should have been far worse—on a scale that could have jeopardized the existence of nations. Yet there's no explanation for why such catastrophic waves didn't occur."

The average depth of approximately 50 meters beneath the sea was initially seen as a conceptual approximation. The research teams had anticipated more variation, imagining scenarios where the periphery of the submerged landmass might be shallow enough to form reefs, while the central regions might be deeply gouged. Such a configuration could explain how incoming seawater minimized tsunami damage through natural buffering by shallow regions. However, this was not the case. Instead, the landmass seemed to have vanished in an inexplicably flat manner. This baffling observation raised profound questions.

Uda's doubts were shared by the British team. Professor Ekman from Sweden participating in the survey remarked, "It's unbelievable, but it seems as though the North American continent was sheared off with an almost terrifying level of precision, leaving an eerily flat seabed."

He speculated further.

"For example, perhaps there was a magma chamber beneath the continent that gradually hollowed out over time. When it could no longer support the weight, the land collapsed. Plato's description of Atlantis sinking due to earthquakes and floods comes to mind. I had thought that North America might have sunk for a similar reason. But I never imagined the resulting seabed would look like this."

The British team concluded that a large-scale diving operation was necessary to observe the phenomenon directly. Human divers equipped with diving suits could reach depths of up to 150 meters, and the team expressed a strong desire to deploy such resources in the future.

"What about the Japanese team?"

"They have surveyed the area where the Rocky Mountains used to be. Even the depth is only about 50 yards (45,7 m) there."

The Japanese team extended their investigations under Uda's direction to a location 400 km beyond Vancouver Island, where Mount Robson once stood. This mountain, the tallest peak in the Canadian Rockies at 3.954 meters, dwarfed even Mount Fuji. Yet here too, the site had transformed into a flat, featureless sea surface with a depth of approximately 45,5 meters.

"Such cold waters."

Previously, the Alaska Current had flowed near Vancouver Island, bringing warmth as an offshoot of the Kuroshio Current, which transitions into the North Pacific Current. This warm current had made the Canadian coastline unusually mild for its latitude. However, the absence of land to guide these currents meant the Kuroshio now veered much farther north, leaving the region to revert to its naturally frigid conditions.

Mount Robson's location at 53°N latitude placed it in a zone prone to rough seas. Historical meteorological data, collected by Japan since the Taishō era, proved invaluable for analyzing these harsh conditions. Unlike the United States, Japan had detailed weather records for the North Pacific, and Britain was eager to obtain this data.

Using the Sōya, Japan launched weather observation balloons, equipped with radio sondes, to collect and transmit atmospheric data. The British team, informed of the transmission frequencies, eagerly received this valuable Pacific-side information. For Japan, possessing extensive historical records, the data offered a means to compare past and present conditions, enabling deeper insights into the changes.

The Sōya continued her survey along the former Rocky Mountains, heading southward. By mid-April, she rendezvoused with a supply ship, replenishing her resources and rotating personnel.

After resupply, the vessel pushed on, eventually reaching the former New Mexico region. Here, a stark contrast emerged: the northern waters were bitterly cold, while the southern seas grew oppressively hot. By this time, Japan had dispatched additional survey teams. With the confirmation that navigation through the area was feasible, the Navy aimed to investigate ocean currents and study the seabed's detailed topography. The increased manpower significantly reduced the workload on the Sōya.

However, the expanded operations caused delays in supply arrivals. It wasn't until July that the Sōya received her next resupply. Hungry for updates, the survey team eagerly read through the newspapers onboard, only to be stunned by the headlines:

Germany-Soviet War Breaks Out!

Hitler Declares Non-Aggression Pact Nullified.

German Forces Advance with Unstoppable Momentum.