A former partner in a top-10 global management consulting firm, Joe Buff is a seasoned risk analyst and professional writer on national security and defense preparedness. He is also a novelist of tales of near-future warfare featuring nuclear submariners and Navy SEALs in action at their bravest and best. Two of Joe's non-fiction articles on future submarine technology and tactics, which appeared in The Submarine Review, received literary awards from the Naval Submarine League. His recent novel Crush Depth made the Military Book Club's Top 20 Bestseller List after being selected as a Featured Alternate of the Club in late 2002. Tidal Rip was released
from Wm. Morrow/HarperCollins in hardcover in November, 2003, and the paperback edition (October, 2004) quickly hit high on the Barnes & Noble bookstores weekly National Bestseller List. Joe's next book, Straits of Power, was published in hardcover in late November, 2004, and before Christmas broke into Amazon's Top 10 Men's Adventure Fiction.
Joe is a member of the Society for Risk Analysis, a non-partisan international scholarly body headquartered in McLean, VA. He is a Life Member of the following organizations: U.S. Naval Institute, the Navy League of the United States, the Fellows of the Naval War College, CEC/Seabees Historical Foundation, and the Naval Submarine League. Joe's father was an enlisted man in the Navy (Seabees in the Pacific Theater) from 1946 through 1951, and his uncle was a merchant mariner on the North Atlantic convoys late in World War II, before being drafted into the U.S. Army to serve in the Occupation of Nazi Germany. In August, 2004, Joe was made an Honorary Life Associate Member of the Navy Seabee Veterans of America, partly in recognition of his pro bono work for Operation Seabees Knowledge. In November, 2004, after having been a guest luncheon speaker at their Annual National Convention, Joe became a sponsored Life Associate Member of the U.S. Submarine Veterans, Inc.
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January 20, 2005
[Have an opinion on this column? Sound off in Military.com
at the Frontlines.]
In olden times, even the best available nautical charts would have unexplored areas of the ocean marked as "Here there be monsters." To mariners of centuries past, practically speaking, this might as well have been literally true: Insurance records from Lloyd's of London show that often during the Great Age of Sail several thousand merchant vessels would disappear without a trace each year, drowning every soul aboard. It's hard for us nowadays to imagine how incredibly perilous sea voyages once really were. It's even harder to picture the anguishing lack of closure for friends and relatives of those whose ships passed over the horizon, bound with high hopes for some far off port or whaling ground, only to vanish forever. Modern technology has tremendously improved both the ships themselves and how they navigate, making cross-ocean travel safer by orders of magnitude.
But as is demonstrated all too well by the recent collision between USS San Francisco -- a Los Angeles-class fast-attack SSN -- and an uncharted underwater mountain near the Federated States of Micronesia island chain, the world's oceans still hold serious hazards for those who go down to, and into, the sea in ships. (Full story) Media discussions in recent days, based in part on information released by the U.S. Navy plus interviews with oceanographers and former submariners, point to holes in the accuracy of available nautical charts as a major factor regarding San Francisco's accident. According to various open sources, other collisions or near-collisions between nuclear submarines and uncharted seafloor topography have occurred in the past.
In this essay, I would like to describe how filling certain gaps, in budgets and in communication cultures, might help prevent or at least reduce problems of this type in the future. I state here that such gaps demand attention because resources are available which might have aided San Francisco to avoid her deadly mishap altogether -- and these resources are being dangerously underutilized. So just what are these resources?
Two distinct methods exist, and have been proven reliable, for efficiently mapping swaths of seafloor terrain without compromising a naval submarine's stealth. Both involve measuring, in very different ways, the local effects of gravity.
Satellite Altimetry: To get started on this interesting topic, first think of Earth idealized, notionally, as a sphere that's slightly fattened near the equator and flat near the poles. This "oblate spheroid" defines a basis for further discussion among cartographers. Terrain features of the actual Earth become bumps and slabs and ripples and cracks of different heights and depths, relative to this spheroid used as a standard of reference. Got that, more or less? Let's proceed.
Specially designed satellites, in orbit for several decades, are able to measure the real height of the ocean's surface at different locations to a precision as fine as an inch. The measurements are done using radar pulses aimed at the water from above. "Real height" means data carefully adjusted for distortions from a multitude of natural phenomena, including variations in the behavior of the ionosphere, the atmospheric humidity along the to-and-fro path of the radar pulse, currents and tides, and constantly changing wave crests and troughs. Compared to the idealized spheroid, advanced computer models construct a three dimensional map of the stable real-height ocean surface -- and that surface, as it happens, is by no means smooth and featureless.
Gravity is an attractive force between masses. Because rock is much more dense that water -- more mass per unit of volume -- seamounts (undersea mountains) exert an extra gravity pull on the ocean around them, compared to an area of ocean where the bottom is uniformly flat. Since water is incompressible, that pull causes the local ocean to pile up over the seamount by as much as tens of meters. For the same reason, a deep trench or fissure produces a weak spot in gravity's pull, and water is drawn away to either side, creating a dip in real height of the ocean's surface miles above the seam in the floor. Scientists have proven that features, on a map of the ocean bottom-terrain created via satellite altimetry, coincide very accurately with known features in seafloor topography mapped by conventional depth-sounding sonar. Each point on the map grid must be overflown by satellites several times -- which because of orbital mechanics can take a year or more -- and the data are then combined mathematically to obtain the best results. The process is therefore neither quick nor cheap, but it's much quicker and cheaper than trying to cover the ocean using research ships -- the National Geophysical Data Center estimates that doing the latter thoroughly would take a century!
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To summarize, through satellite altimetry it's possible to produce what's called "pseudo-bathymetry" -- a nautical chart of the ocean's depths derived solely by surveillance from outer space, on which a typical seamount would stand out clearly. Agencies involved in this work include NASA, NOAA (the National Oceanic and Atmospheric Administration), and the U.S. military. Satellites used in these efforts have included the pioneering Geos-3 launched in the 1970s, Geosat in the 1980s, the European Space Agency's ERS-1 and ERS-2 from the mid-1990s, and the U.S. Navy's GFO since 2000. Portions of the mapping results, and details of ongoing studies, remain classified. However, one may conjecture, as I do, that some of this data might have prevented San Francisco from hitting the seamount.
And it turns out, according to a civilian geophysicist interviewed in the New York Times on 15 January, that there is indeed some indication of a seamount at the crash site in radar altimetry obtained in the mid-1980s. The data, though, was described as having a large margin of error and being too vague. I would not presume to disagree with this caveat. I would say that, at a minimum, there ought to have been a notation on the San Francisco's charts, last updated in 1989, to the effect of "Here there be possible uncharted seamounts" -- and there wasn't. Furthermore, given progress since the mid-'80s in so many aspects of aerospace and radar engineering, downlink baud rates, and supercomputer speeds, data obtained much more recently (by GFO?) might show the location of that seamount with no ambiguity. My conjecture -- which is only that -- as stated above still holds.
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