(AUTHOR'S NOTE)  The word seaquake is often misconstrued and used improperly.  Some writers incorrectly refer to a tsunami as a seaquake.  Others wrongly define a seaquake as any earthquake in the seafloor.   Even scientists confuse the issue.  For example, seismologists first recorded mysterious vibrations in the 1930's on their land-based seismographs situated near the coast.  Not knowing the source, they called these strange signals  t-phase waves simply because they were the "third" set of wiggly lines to arrive at their land-based instruments (following p-waves and s-waves).  These early investigators finally determined in the 1950's that the enigmatic waterborne vibrations were low frequency hydroacoustic (compressional) waves generated by distant earthquakes in the seafloor.  T-waves departed the epicenter of an earthquake in the seabed, traveled thousands of miles in the SOFAR channel to strike the edge of the continental drop-off and then re-enter the solid earth to impinge on shore-based seismic instruments.  But rather than change the name "t-wave" to better fit the origin and oceanic travel path of this energy, the seismologists stuck with the terminology and later expanded to include pressure waves produced by large man-made explosions.

Scientists monitoring nuclear testing in the oceans have recently refined their terminology.  According to this group, sound waves in the ocean can now be one of three types of signal: H-phase, T-phase or N-phase. H-phase signals come from in-water explosions caused either by man-made devices or underwater volcanic eruptions. T-phases are waves generated by distant earthquakes. They are formed when seabed vibrations caused by the earthquake send sound into the water. N-phase signals are noise signals from a wide range of physical sources such as iceberg-generated noise, airgun surveys and whale song.

The Deafwhale Society prefers the word seaquake as originally coined in the 1888 by Eberhart Rudolph, Professor of Geophysics at the University of Strassburg in Germany.  He defined seaquake  as an earthquake "felt" by crew members on a vessel.  We diverge slightly from Professor Rudolph's original concept and define a seaquake  as a series of alternating pressure waves induced into the water by a submarine earthquake, volcanic eruption, or the impact of a meteorite with the ocean's surface.  (For more info search Google,  Google Scholar, and/or Google Books using "seaquake" and "earthquake T wave" as keywords.)

INTRODUCTION

The world's seismic databases were reviewed from 21 February 2000 to 31 March 2008.  The earthquakes extracted from the eight years of data were plotted as dots on the map below.  The ones in red represent shallow-focus events. 

The dark blue areas in the map above depict an undersea mountain range known as the Mid Ocean Ridge System.  These volcanic mountains stretch continuously for ~40,000 miles around the globe like a seam on a baseball.  The dark blues "seam" is positioned at the boundaries between the world's 29 tectonic plates. 

Close comparison of the two maps clearly shows that ~ninety percent of all earthquakes on our planet take place under the ocean's surface along this chain of undersea mountains.

The mid ocean ridge system is where hot liquid rock flows up from deep inside the planet.  Sometimes, the melted rock comes out with a great burst of pressure that forces apart chunks of the seafloor in a violent submarine earthquake.

This volcanic mountain chain is by far the most biologically abundant feature in the ocean. 

Here's another fact--the red dots overlapping the deep blue color in the two maps above encompasses the backyard of the whales and dolphins known to mass strand.  Pods of mass stranders hang out along these ridges. They dive down deep and feed on squid that are attacked to the area by the great diversity of life. 

Mass stranders have made their home in this area for ~20 million years.  And, as far as we know, have been stranding en mass ever since.  That these pods feed daily a ~thousand meters below the ocean's surface, above the most earthquake-prone areas on the planet, is the best possible clue to explain why they mass strand. 

Up until recently, scientists were convinced that explosive eruptions of this nature were not possible along the mid ocean ridges because of the increased water pressure at depth.  In fact, it was not until 2006 before magma chambers were discovered along the slow spreading Mid-Atlantic Ridge.  Only in the last few years have scientists begin to see the fallacy of their previous thinking.  We now know that explosive volcanic/tectonic earthquakes occur in water deeper than 4,000 meters (explosive eruptions in the deep sea).  If fact, scientists have recently been able to photograph a deep sea volcanic eruption.

But do not imagine that a loud impulsive noise is the cause of the injury.  Mass stranded whales are not deafened. Rather, when the seafloor dances vertically during an explosive mid ocean ridge earthquake, the vertical movement in the rocky bottom presses against the water column like a giant piston, generating rapid changes in the ambient pressure in the water above the epicenter.  It is the rapid changes in water pressure, called seaquakes,  that cause injury in the diving whales.  (read more on explosive earthquakes in the seabed)

Seaquakes (rapid changes in water pressure) differ in intensity depending on several variables the least of which is the magnitude of the earthquake.  One of the most influential factors determining the intensity felt by the whales is the depth of the earthquake's hypocenter (focus).  In general, if a mid ocean ridge earthquake is focused deeper than 10 kilometers, the energy tends to spread out and dissipate in the solid earth as it fans out in an upward direction toward the water interface.   Whereas events hypocentered at 5 km deep release far more seismic energy in the hydrospace simply because there is less loss energy due to spreading.  In general, the intensity of a seaquake is doubled if the depth of focus is halved.  Said differently, a depth of focus of 5 kilometers will produce seaquake intensity twice as great as a depth of focus of 10 kilometers. 

Naturally, the most dangerous undersea earthquakes are those in which the rupture extends to the rock/water interface. 

Some of the largest mid ocean ridge earthquakes of recent time are characterized by predominantly normal and reverse-thrust faulting on planes that dip at approximately 45° and strike parallel to the local trend of the ridge axis. The mean depth of focus ranges from 1 to 15 km beneath the seafloor.  These events often rupture through the seabed.  The "P" waves measured at land-based seismic stations from these shallow earthquakes show strong water column reverberations (these reverberations are seaquakes), suggesting that often the fault rupture does indeed extend to the rock/water interface (ref).  Seaquake reverberation in the water column are often reference as Pwp waves (primary/water/primary).

Another important factor in determining seaquake intensity is the speed of any vertical thrusting motion.  If there is a slow moving vertical component, the water above the epicenter has more time to flow to the sides or edges of the epicenter thereby preventing potent seaquake pressure waves from building.  On the other hand, when a small section of the hard basaltic bottom explodes violently in a vertical direction in response to a build up of pressure from a magma chamber below the rock/water interface, alternating seaquake pressure waves directly above the epicenter might exceed 14,500 pounds per square inch (280 decibels re 1 micro PA) one meter off the bottom.

Most folks have no mental grasp of the pressure contain in a 280-decibel signal, but they quickly understand 14,500 pounds per square inch.  This is why the US Navy and the oil industry keeps talking about deafness and decibels.  They want to avoid the simpler "pounds per square inch" and the barotrauma associated with a pressure related injury.  The reason the oil industry does not want folks thinking about such great pressure waves and barotrauma is because oil industry seismic airgun arrays towed behind seismic survey ships generate pressure waves that often exceed 15,000 pounds per square inch.  The boom boom boom boom every ten seconds from an airgun array is identical to the same seismic waves generated by an undersea earthquake.  In other words, the oil industry generates somewhere near a million powerful seaquakes per week, 52 weeks per year.

The US Navy and the oil industry do not want to discuss non-auditory consequences (barotrauma) resulting when a diving whale is exposed to rapid pressure changes.  They say this is because the ear is generally assumed to be the physiological system most sensitive to loud noise and therefore most vulnerable to damage by intense sounds. Yet, there are far more plausible ways in which low frequency compressional waves (infrasound) might affect anatomical structures and physiological processes other than via damage to the cochlea and middle ear.  However, the US Navy and the oil industry purposefully avoid any discussion of the infrasound and of the Seaquake Hypothesis.  They use the excuse that seaquake injury is not discussed in reference journals; therefore, they can turn a blind eye to seaquakes and be technically in clear.  As long as they can keep the Seaquake Hypothesis out of main stream scientific journals, they can continue to ignore this work regardless of how stupid they look turning their back on underwater earthquakes as a source of injury in whales. (read more on how sonar causes injury in whales)

And don't expect to see a lot of support for this work from marine mammal scientists.  The US Navy and the oil industry control 90% of all the research funds spent to study whales.  Any scientist who supports a view opposing these two powerful groups will end up being black listed and starved out of the business.

But every now and then, work does get published that unknowingly supports the Seaquake Hypothesis.  For example, here is an abstract that will further enlighten you on the importance of intact head and middle ears sinuses.  M.R.  Clarke,  a UK scientist, wrote:

"The detailed anatomy of the noses of Kogia breviceps and K. sima (Kogiidae: Cetacea) is described in greater detail than previously. Probable functions of component parts of the nose are deduced from their geometry and physical properties of the tissues. It is concluded that control of the air making the sound is similar to that found in Scottish bagpipes with a single reed, that sounds are produced by air being forced from the vocal valve and is resonated in an unusual chamber having cords and membranes, similar to human vocal cords. It is then reflected by air filled ‘mirrors’ and conducted and intensified through a megaphone-like ‘horn’ which is surrounded by air and contains tissues rich in spermaceti oil. Sound then passes through the melon where, by changes in temperature of the spermaceti oil, it is actively focused and possibly scanned. Thermal properties of Kogia spermaceti oil are described and related to previously made sound velocity and density measurements. The way sound production and reflection can continue while large variations of pressure are experienced during deep dives, is suggested. A structure for controlling the temperature of the melon is described. It is considered unlikely that the spermaceti oil is used for buoyancy control in Kogia. Some comparisons are drawn with Physeter catodon, Xiphius and Tursiops and some implications for research on other cetaceans are outlined."

He concluded that the the clicks of many whale species are produced by air being forced from the vocal valve and is resonated in an unusual (air) chamber having cords and membranes, similar to human vocal cords. It is then reflected by air filled ‘mirrors’ (pterygoid sinuses) and conducted and intensified through a megaphone-like ‘horn’ which is surrounded by air and contains tissues rich in spermaceti oil.  Sound then passes through the melon where, by changes in temperature of the spermaceti oil, it is actively focused and possibly scanned.  In this fashion, sound production and reflection can continue while large variations of pressure are experienced during deep dives.  In other words, functional, intact, healthy, head sinuses filled with air play the major role in not only sensing sound (hearing) but in sending sound waves as well.

Bottom line is that excessive changes in ambient pressure (seaquakes) cause barotraumatic injury to the auditory head sinuses in diving whales.

Squid, the favorite food of deep diving whales, breed and lay their eggs along the mid ocean ridges mostly because the molten rock heats the bottom waters to ~8° centigrade, the preferred temperature for hatching squid eggs.  Squid are not injured by rapid pressure changes because they have no enclosed air spaces.  On the other, the preference of air breathing whales and dolphins for squid, places them at great risk of one day being exposed to a sudden pressure change generated when the seafloor is suddenly thrust upward in a violent eruption.

Not only are the whales subject to an instant increase in pressure, they are also exposed to a sudden and severe decrease in ambient pressure.  Often, shortly after the seafloor cracks open, releasing an immense positive pressure pulse, the top of the magma chamber will collapse inward creating a sudden drop in ambient pressure that can be far more hazardous to diving whales than the initial shock wave.  Exposed to this sudden decompression, air inside the sinuses cavities in the heads of feeding whales can expand to 2-3 times their normal surface volume.  Thus, seismic events associated with the sudden expansion/cave-in of a magma chamber along the mid ocean ridge axis can expose deep diving squid feeders to dangerous changes in ambient pressure that could easily induce barotraumatic rupture in the head and middle ear sinuses of each member of the pod.

The entire pod is injured--not just the pod leader.

The one consistent observation the no other theory has been able to explain is why whales mass strand on certain beaches during what appears to be a 3-month season.  To make matters even more complicated, the seasonal stranding pattern is different depending on the area.  The Seaquake Hypothesis can easily explain this seemingly odd consistency.  There are several factors that combine to establish the pattern.  First and foremost, potent earthquakes along mid ocean ridges are seasonal and tied to the average height of the wave action.  The ocean's surface, the atmosphere, and the seafloor are all connected (full article - abstract).  High waves during the winter storm season in the northern hemisphere interact to form oceanic infragravity waves that wham into the seafloor, setting off shallow-focused earthquakes in areas where there was already an increased buildup of tectonic stress.  The infra waves serve as the straw that broke the camel's back. 

Oceanic currents also change directions seasonally, as does the wind.  In one season, earthquake-injured whales would swim with the current to a different beach.  Whereas, during a different season, the pod is carried off in an entirely different direction.  The squid also migrate up and down the ridge system on a seasonal basis depending on currents, water temperature, and other factors known only to the squid.  This means that pods of deep diving whales and dolphins following the season movement of the squid in and out of earthquake-prone areas and in and out of harms way.  Put all the variables together and it becomes clear why certain beaches have a stranding season and other beaches don't.    

Why the mystery was not solved 50 years ago is shameful.  Scientists have known for decades that something ferocious was going on in the seafloor.  For example, none other than the Director of the Scripps Institution of Oceanography in San Diego, Professor Harald Sverdrup, wrote over 60 years ago on Page  543 of his famous book "Oceans" the following:

        "Waves in the sea caused by earthquakes are of two different types. In the first place a submarine earthquake may produce longitudinal oscillations that proceed at the velocity of sound waves. When reaching the surface, such longitudinal oscillations will be felt on board a ship as a shock that violently rocks the vessel. The shock may be so severe that the sailors believe their vessel has struck a rock, and several such reported “rocks” were indicated on early charts in waters where recent soundings have shown that the depth to the bottom is several thousand meters. There are many ship reports dealing with shock waves, particularly from regions in which seismological records show that submarine earthquakes are frequent."

Seismologist T. Neil Davis at the Geophysical Institute, University of Alaska Fairbanks describes an earthquake felt on board a ship as:  "Almost universally, reports by people on ships tell of having thought that the ship had run aground. Rumbling, grating sensations and horrifying rattling of ship superstructures are reported. The noises often appear to come mainly from the bottom of the ship, and there is fear that the ship is breaking up." (Alaska Science Forum). 

Seismologists J. Northrop and R. W. Raitt with  SCRIPPS INSTITUTION OF OCEANOGRAPHY in San Diego reported in the Bulletin of the Seismological Society of America that a series of distant (50-400 km) seaquakes in the Flores Sea, (at ~10 cps and lasting from 20 seconds to 4 minutes) overloaded the seismic recording equipment they were using to record 100-pound shots of TNT.

On the subject of TNT, a magnitude 4 earthquake in the seabed corresponds to an explosive yield of about one thousand tons (1 kiloton). There is roughly a 30-fold increase in seismic energy for each step up in magnitude.  A magnitude 5 earthquake releases as much energy as the Hiroshima atomic bomb — the equivalent of 32 kilotons of TNT. A magnitude 6 is equivalent to 30 Hiroshima bombs.  Alternatively, a magnitude 7 quake releases about a million times more energy than a magnitude 3 quake. (Source GNS Science)

The famous Harvard mathematician and Deputy Director for Goddard Space Flight Center, John Quann, and two colleagues, published an article in 1972 suggesting that a seaquake shock wave generated above the epicenter of a magnitude 7.5 earthquake approached 6 kilobars (6,000 atmospheres) and raised the temperature of the water 3 degree kelvin for 20 miles in all directions.  (6 kilobars = 90,000 psi) 

 To repeat, magnitude naturally contributes to the level of danger faced by a diving pod but magnitude is not controlling.  What determines the potential for harm is the rapid fluctuation in water pressure (seaquakes) measured in pounds per square inch.  The intensity of the pressure changes are mainly determined by the SPEED of the seafloor displacement coupled with the DEPTH of the hypocenter where the main seismic slip takes place.  Naturally, the DISTANCE from the epicenter to the diving pod is also critical.  Said differently for clarity, lightening-fast vertical jerking hypocentered very close the rock/water interface generates far greater change in surrounding water pressure (seaquake) than does slower/deeper seismic motion. 

In general, Richter magnitude corresponds to the length of the rupture and serves more to determine the circumference of the danger zone, not the degree of hazard faced by any nearby pod.  A larger magnitude shallow-focused quake is more likely to injury whales simply because the zone of danger is far greater.  

The intensity of these vertical-traveling compressional waves (seaquakes) rapidly dissipate as the waves speeds toward the ocean surface at 1,500 kilometers per second.

THE BENDS IN WHALES

Not only must the diving whales deal with a sudden increase in water pressure, they must also deal with a sudden decrease in pressure. Seaquake dilations (negative pressure phases) can easily cause cavitation bubbles to form (bends) in the soft tissues and blood of the whales, especially after a relatively long dive.

A shallow undersea tectonic earthquake, or the surface impact of a small meteoroid, produce identical affects and are thus part of this theory.  However, the Deafwhale Society is under the opinion  that explosive volcanic/tectonic earthquakes cause 90% of  all mass strandings.

Just as it would be if a large group of scuba divers were suddenly exposed to rapid pressure changes from a nearby disturbance, a pod of diving whales caught off-guard by rapid and excessive changes in the surrounding water pressure during vertical thrusting of the seafloor are subject to barotraumatic injury in their head and middle ear sinuses when the rapid changes in pressure exceed the whale's ability to adjust. (read more on the seaquake encounters)

As mentioned above, of particular concern are the small air sacs (pterygoid sinuses) that surround each cochlea and help the whales sense sound direction underwater.

Intense oscillating disturbances in ambient water pressure can cause the volume of air in the head sinuses to expand and contract to the point of an injury.  A whale with a tear in its pterygoid sinuses would hear sounds perfectly well, but would not be able to determine from which direction the sounds came. Ruptured sinuses would also disrupt feeding since the trauma would prevent the whales from diving to the depth of their prey due to extreme pain.

Diving-related injuries of this nature are far more common than one might imagine.  The injured pods are forced to remain on the surface until their sinuses heal.  They might not be able to resume diving and feeding for days, or weeks, or maybe not at all depending on the degree of injury and the availability of food and fresh water on or near the surface.

Offshore whales normally fix their location along the Mid Ocean Ridges by “listening” to the constant seismic rumble going on below them.  Their acoustic locating abilities are lost when the pterygoid sinuses are ruptured.   Specifically, the position of the large pterygoid sinuses, a fibrous venous plexus, and a lipid-rich pathway that connects the acoustic environment to the inner ear complex indicate that the large pterygoid air sinuses are essential adaptations for maintaining acoustic isolation and auditory acuity of the ears at depth. Thus, a pressure related injury in these sinuses would affect all the adult members of the pod, resulting in the pod being acoustically lost at sea.

The question now is which way would a pod of lost whales swim.  The answer is simply and not subject to debate.  In a three knot current, the flow of the water offers ten times the resistance when swimming upstream as it does when swimming downstream (ask any scuba diver). Thus, without a sense of direction on the part of the pod, the resistance factor would quickly turn the streamlined bodies of each animal head first and keep them pointed in a downstream direction in a similar fashion as how a wind vane always points the direction of the wind. Said differently, the lost pod can not prevent traveling downstream in the path of least resistance. In fact, they are eventually stirred by reduced resistance into the center of the fastest downstream flow where they remain until some other factor causes a change of direction. Thus, the swim path of the seaquake wounded pod is controlled by the surface currents and the wind and nothing else--especially not an imagined geomagnetic compass.

In absolute fact--beached whales are carried to a sandy beach by the same force that carried each grain of sand to build the beach in the first place. 

If the surface winds and/or the tidal flow causes a change in the flow of near shore surface currents so will the swim path of the whales change. 

The whales might change course from the flow of the current if frightened by nearby ships or if chased aggressively by sharks, but this course change is quickly reversed by the current when the danger eases.

Geographic land masses that extend out to see opposing the flow, like Cape Cod in the US and Golden Bay in New Zealand, serve as giant catching arms, guiding the non-navigating whales into a sand trap.

The wounded pod naturally attracts the attention of large oceanic sharks that move in to take any stragglers. Deep water sharks grow big by feeding on wounded whales, not squid. The hungry predators "dog" these pods like wolves dog a herd of caribou, forcing them to huddle together for protection as they continue to swim in a general downstream direction.

The danger of shark attack to surfers and swimmers increase a hundred fold when seaquake-wounded whales are carried near shore by local currents.  Paying attention to the Seaquake Hypothesis will indeed save the lives of human visitors to the sea.  Ignoring this work will result in a continuation of shark attacks along popular beaches.

Make no mistake, pelagic whales and dolphins have evolved for millions of years in seismically active water.  The animals have made adaptations to seaquake pressure waves. (evolutionary adaptation to seaquakes) 

Some pods recovery within a few days. Others within a few weeks. Those that do not recover stand an excellent chance that the surface currents will eventually carry them to a sand trap, especially a sandy beach inside a large strip of land that extends out in a fashion opposing the flow of the current.   All the world's major stranding sites form a catching-arm system.  These sites also just happens to be located downstream from a seismically-active feeding ground for the species in question.

Why Do Sea Turtles Have Ears?

Did you ever hear of a deaf sea turtle? Do you have any idea what would happen to a deafened sea turtle? Exposure to excessive pressure waves generated by oil industry seismic airguns is the leading cause of sea turtle mortality and the US Government is covering it up! click here to read about deafened sea turtles

CAPT David Williams

DEAFWHALE SOCIETY, INC.

Box 319, Dumaguete City

6200 Oriental Negros

Philippines

THE MARY CELESTE MYSTERY SOLVED