Subterranean Secrets: Trinidad’s Mud Volcanoes

Trinidad’s feisty mud volcanoes are known for their unpredictability, but few people consider them attractive. Maura Imbert wonders if their true beauty is simply awaiting discovery

  • The mud volcano landscape of Piparo, south Trinidad. Photograph by Maura Imbert

I’m looking at a photograph of three pelicans perched on top of the mud volcanic
island in Trinidad’s Chatham Bay, which erupted on May 10, 2001. Browsing
on the Internet, I’ve also found photos of a Trinidadian mud volcanic island
in the Columbus Channel, which jutted about three metres above sea level
on its fourth rising since 1911, and of a spectacular eruption of the Piparo
mud volcano, the first ever captured on film, which occurred on February
22, 1997.

Looking at these photographs, or at the bubbling mud volcanoes themselves,
the facetious would probably remark that Mother Nature seemed to be suffering
from a bad bout of indigestion, or what we in Trinidad call “gas”, and since
the mud volcanic eruptions are always accompanied by the churning caused
by escaping methane gas, the observation might not be too far off the mark!

The Earth, however peaceful it may seem in some idyllic Caribbean setting,
is far from tranquil below the surface — a fact amply demonstrated by the
presence of hot sulphurous springs and geysers in many parts of the world,
active volcanoes erupting molten lava, and the terrestrial shudders of earthquakes.
Mud volcanoes are a milder indication of the pent-up pressure below the earth’s
crust, which is so often released in a devastating way. Instead of lava,
an extrusion of watery mud, clay, and gas erupts from a subsurface layer,
and this material builds up a solid deposit around its orifice. The eruption
is considered to be mainly due to the increasing pressure of the Earth’s
crust on the wet, subsurface mud and shale, and the presence of pockets of
methane gas, and is sometimes associated with oil. Geologists, however, consider
mud volcanoes unpredictable, and there is still considerable controversy
about their origin and bouts of activity.

Strangely enough, the subject of mud volcanoes arose when, intending to write
about diamonds, I enquired of Dr J.C. Knight of the physics department at
the St Augustine campus of the University of the West Indies about current
departmental research in crystallography. My mind was filled with the scintillating
sparkle caused by refraction inside diamonds and other beautiful gem stones,
due to their crystal structure; and no one was more surprised than I when,
instead of talking about diamonds, I found myself discussing how crystallography
was used to analyse mud from mud volcanoes.

The mud is considered to be a potential raw material for ceramics manufacture,
and the UWI physicists are investigating the effluent from the Devil’s Woodyard
mud volcano of central Trinidad.

X-ray diffractometry shows that the effluent is essentially kaolinitic clay.
There is a mound of about 25 to 50 tonnes of grey, fine-particle, sun-baked
effluent at the site — a gift to man mined by nature, and ready for use should
it prove suitable for the manufacture of ceramics. The low costs associated
with its removal, or the removal of mud from other mud volcanoes which do
not have potential as tourist attractions, would be a decided economic advantage,
and would not have to involve open-pit, quarry-type mining, with its often
unsightly aftermath.

Mud volcanoes are tourist attractions in many parts of the world, particularly
around the Caspian Sea. In Azerbaijan, in the southern Caucasus, there are
hundreds of mud volcanoes of all shapes and sizes, which constantly emit
mud, water, and gas, and which are considered to be amazing and even beautiful
sights. They invariably form part of the tourist itinerary in the region.
Now and again a mud volcano there explodes with great force, shooting flames
hundreds of metres into the air and depositing tonnes of mud in the surrounding
area. But there are no reports of any removal or use of this mud in Azerbaijan.

The mud from the Devil’s Woodyard, a highly plastic kaolinitic clay, possesses
“potentially high strength,” according to Dr Knight, and “high toughness
products are possible from Devil’s Woodyard mud at a much lower firing cost
compared with the firing of most normal Trinidad clays to equivalent strength
and toughness”. Perhaps Trinidad will lead the way in the utilisation of
this gift from nature.

I must admit that I returned from my visit to UWI’s physics department in
a somewhat bemused state, having gone there seeking information on the magic
of a diamond’s sparkle, but returning with information about mud! I had to
remember that diamonds are also formed  within the Earth’s crust, under
conditions of extreme pressure, and that, like volcanic mud, they are often
pushed towards the surface by various Earth movements. Like mud, diamonds
— which look like dull pebbles in the raw state, and only reveal their beauty
when cut and polished — attracted very little attention when first discovered
by early man. Perhaps, in a similar way, the hidden potential of the mud
from Trinidad’s mud volcanoes will only be revealed when this natural substance
is moulded and fired into beautiful ceramics.

A further dimension to mud volcanoes has recently been revealed in the North
Atlantic. A hot mud volcano on the sea floor between Greenland and Norway
is oozing mud, gas, and warm water into the ocean but, strangely, a cap of
frozen methane sits on top of the volcano, leading geophysicist Kathleen
Crane to call it a “baked Alaska”, thanks to its resemblance to the popular
dessert. Stranger still, a new species of tube worm lives on the slopes of
this volcano, extending tube-like projections into the surface and feeding
off the seeping methane and hydrogen cyanide gas — normally a poison to terrestrial
life forms. It has been found that bacteria living inside the worms in a
symbiotic relationship actually do the feeding, and provide life-giving energy
to their hosts.

The unusual diet of the worms and bacteria brings to mind the fact that methane
is plentiful on certain planets and satellites in our solar system, including
Uranus, Neptune, and Saturn’s giant moon,

Titan. The latter has a thick atmosphere containing methane, and, it is thought,
oceans and lakes containing hydrocarbons. It is postulated that the land
protruding above these oceans is covered with “sticky tarlike goo”. Could
there be alien space-worms crawling along the slopes of this “goo”?