Bledug Kuwu mud volcano spouts salty water, local lore

Bledug Kuwu mud volcano spouts salty water, local lore

Bambang M, Contributor, Grobogan, Central Java

Bledug Kuwu looks like just another muddy pond. But every one or
two minutes, the placid water erupts in an explosion of mud,
followed by a plume of white steam.

You can find this natural wonder near Kuwu village, 28
kilometers east of the town of Purwodadi. The pond is located
just off the alternative road connecting Purwodadi and Cepu in
Central Java, on a site measuring some 4.5 hectares. Bledug Kuwu
has become a tourist attraction in the area.

Visitors can watch the geyser from a distance of between 10
meters and 20 meters. The eruptions of water and mud shift
positions from time to time. But there are two spots where the
geyser regularly erupts. The locals call the one in the east Mbah
(Grandpa) Jokotua and the one in the west Mbah (Grandma) Rodenok.

They have given the spots where the geyser erupts names as
they believe that the place is sacred.

The geyser brings salty water up to the surface from the
bowels of the earth. This water actually contains a higher level
of salt than that of the sea.

Locals obtain salt from this water, and the visitor can watch
the traditional process taking place. The salty, yellowish water
that spouts from the earth is funneled along a bamboo channel to
a teakwood container measuring four by four meters.

There are dozens of two-meter-long bamboo cuts joined together
to form a channel of about 50 meters long. The water is then
allowed to evaporate. Within one week, the water is all gone and
all that is left is the salt.

"It's about 50 kilograms," said Suliyem, one of the salt
workers, referring to the amount of salt she obtained weekly.

The salt produced this way is so tasty that it is said that
the cooks from the old Surakarta Kingdom always used salt
produced in this area.

Bledug Kuwu is a must-see spot though the area is almost
devoid of tourist facilities. Despite the blistering heat, the
pond is unique in the sense that it one of the biggest geysers in
Java.

Jarot Setyowiyoto, a lecturer at Gadjah Mada University, said
that there was also a pond in Djuwangi, Boyolali, which also was
home to a geyser, although its eruptions were smaller. Larger
eruptions also used to take place in Sangiran.

"Geologically, the phenomenon the you see in Bledug Kuwu is
known as a mud volcano as it blows out mud from deep inside the
earth," Jarot said.

He said that there were two possible explanations for the
phenomenon.

First, a phenomenon known as a shale diapiric process, where
the ground slowly sinks into the earth, thus producing eruptions.

Second, because gases from the earth or biogenic gases react
and generate high pressure gas that has to find a way to escape
to the surface.

The gas usually emerges where the soil is weak, such as in
Bledug Kuwu.

"The gas build up under the mud. When the pressure is high
enough, it pushes through the mud," he said.

And what about the salty water?

Jarot said that when the gas is seeking the way out, it passes
through a layer of stone that geologically has trapped sea water
underneath it for millions of years. The water is then pushed up
to the surface by the pressure of the gas.

Such water usually has a high salt content. The water in
Bledug Kuwu contains 8 ppm (parts per million) of salt, compared
to the sea water which has a degree of 3 ppm.

Another interesting fact about the Bledug Kuwu geyser is that
at the center of the eruptions, where the temperature is between
28 and 36 degrees Celsius, bacteria are found that are similar to
one living in the depths of the ocean off Japan.

"The bacteria found there (in Bledug Kuwu) are extremely
resistant. They are halotolerant, or capable of resisting high
levels of salt," Endang S. Soetarto, a microbiologist from Gadjah
Mada University, explained.

But the residents of Kuwu village know nothing about the
bacteria or the scientific explanations for their geyser. If you
ask them about the phenomenon, they will tell you about the
legend of Aji Saka, the king of Medang Kamolan Kingdom, which
stood close to Kuwu village.

It is said that the son of the king took the form of a snake,
who was called Joko Linglung. Aji Saka was ashamed of his son. So
he told Joko Linglung that he would only recognize the snake as
his son if he killed his father's enemy, a white crocodile in the
South Sea. The king also said that if Joko Linglung killed the
crocodile, he should return home through an underground route.

Joko Linglung agreed and he finally managed to kill Dewata
Cengkar, the white crocodile. He then crept home through an
underground passage. Arriving in Bledug Kuwu, he emerged to the
surface to take a rest and find out where exactly he was.

The locals believe that the hole from which he emerged is
where the geyser now erupts, and the salty water is water from
the South Sea which flows through Joko Linglung's underground
passage.

Because the sound of the geyser erupting is like the explosion
of a canon, the people called it Bledug, while Kuwu comes from
the word pakuwon, which means "resting place".

Near Bledug Kuwu is the sacred grave of Mbak (Sister) Ro
Dukun, or Raden Ayu Ngainah, the woman who took care of Joko
Linglung when he was resting in the area.

The villagers believe that her spirit is still dwells in
Bledug Kuwu.

"If the residents of Kuwu village want to hold a party, the
must place offerings at Bledug Kuwu first. If they don't, then
there will be problems," said Suliyem, a mother of two.

Whatever you think of this story, one thing for sure is that
the salt produced at Bledug Kuwu is excellent.

"This salt can also cure stomachaches. Just put one teaspoon
of salt in a glass of hot water and drink it," said Sukinan,
Suliyem's husband.

Some villagers also sell the saltwater from Bledug Kuwu, which
is said to also cure skin ailments. If you are skeptical, why not
try for yourself at Bledug Kuwu.