While drilling companies focus on extracting natural gas buried deep in the
Mediterranean’s core, a geophysics research team from the University of Haifa
has discovered a series of active gas springs leaking on the Haifa Bay sea
floor.
The springs are located at relatively shallow depths, just a few
dozen meters below the surface of the seabed, the researchers learned in their
study, which was recently published in the journal Continental Shelf
Research.
After examining a sea floor map of Israel’s northern coast, the
researchers first identified that there might be springs in the area, according
to the university.
A joint effort with the Israel Oceanographic and
Limnological Research Institute then ensued, revealing around 700 spots in the
floor that might be gas springs.
Seismic data also showed that there were
pockets of gas located beneath the seabed, university information
said.
“This is a natural laboratory for researching gas emissions from
the sea floor – natural springs and less natural ones,” said Dr. Uri
Schattner of the Leon H. Charney School of Marine Sciences at the
University of Haifa, who led the research. “We are only beginning to understand
their contribution to climate and ecological change.”
With all of this
evidence, the researchers then took to the sea – exploring four times to collect
data from both on and below the floor. There, they found a gas deposit of 72
square kilometers on the continental shelf, in areas with water depths of
between 37 and 112 meters, 10 meters below the sea floor. There is essentially a
“cloud of gas” in the water, and then most of the gas is in pockets that extend
up to 10 meters below the sea floor, in the mud, Schatter told The Jerusalem
Post on Thursday.
“It’s something you overlook because normally you go to
the deep sea,” he said.
Although deep sea drilling can cause these types
of gas leaks and these have occurred in other parts of the world, the drilling in
the Mediterranean did not cause these springs, which are, in fact, natural,
according to Schattner. While the researchers know that there is plenty of gas
down there, they do not know exactly what kind of gas it is.
Thus far,
scientists have no idea if this new gas will be useable, as they first must
trace the source of the gas, Schattner explained.
“I don’t mean only
where does it come from in the subsurface, but what processes formed this gas –
is it biogenic, is it thermogenic, does it say something about a very deep oil
reservoir, or maybe it just comes from layers that are very rich with organic
material,” he said.
No matter what type of gas it is and where it comes
from, however, “Its role in undermining the stability of the seabed is clear,”
said Dr. Michael Lazar, a member of the research team.
“This means that
any discussion of marine infrastructure development must seriously relate to
this shallow gas stratum,” Lazar added.
The existence of this deposit
becomes especially critical as the Energy and Water Ministry formulates a
National Master Plan to deal with the transmission of natural gas from their
deep-sea drilling sites to their pressure-reducing facilities, which will be
located on the continental shelf, the researchers explained.
“Now we are
beginning to understand that there is no substitute for thoroughly researching
the stability of the sea floor to prevent an infrastructure failure, since any
leak could cause an ecological disaster,” Schattner said.
There are many
different causes of instability on a sea floor, but shallow gas is certainly one
of them, and can have a significant impact on designing infrastructure and
determining financial factors like insurance, Schattner explained.
“Just
think about building a hospital on quicksand,” he said. “It’s something that
should be taken into concern and as we speak we are in conversation with the
Energy and Water Ministry. They know about our work and we know about their
concerns.”
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