World / Israel

Falling Again.

Dani Machlis/Ben-Gurion University

Scientists try to assure stability

of historic site, Masada.

Sue Fishkoff
Jewish Telegraphic Agency

Masada, Israel

M

asada is one of the
most renowned sym-
bols of Jewish endur-

ance.-
Rising 750 feetabove the Dead
Sea valley, the site of a mass sui-
cide of Jewish zealots in 73 . C.E.,
it is, next to Jerusalem, Israel's
most popular tourist site. Elite
units of the Israel Defense Forces
hold special ceremonies atop its
heights, pledging, "Masada shall
not fall again." •
But it might.
Not today, not tomorrow, but
one day, as seismic tremors,
climatic change and, inevitably,
gravity continue to threaten the
stability of the historic ruins and
the mountain that supports them.
Engineering professors
from Beersheba's Ben-Gurion
University of the Negev and the -
University of California-Berkeley
have teamed up to make sure that
doesn't happen.
Using state-of-the-art moni-
toring devices and advanced
computer modeling techniques,
and armed with a four-year . grant
from the United States-Israel
.
Binational Science Foundation,
Beersheba's Yossi Hatzor and
Berkeley's Steven Glaser are
breaking new ground in geologi-
cal engineering. Masada is their
test case.
"Masada has been degrad-
ing for 2,000 years:' says Hatzor,
head of BQU's Rock Mechanics
Laboratory and founder of the
geological engineering team
working on the problem."There's

28 May 11 • 2006

no Imminent danger," he adds.
"Nothing is collapsing. We're talk-
ing about long-term preservation
of a World Heritage site?'
The imposing, reddish-gold
mountain sits directly on the
Syrian-African Rift, an active
earthquake fault line. Since Herod
the Great built his luxury palace
on the mountain's northern face
more than two millennia ago,
at least five major earthquakes
have hit, causing rock slides and
some damage to the man-made
structures. Harsh desert weather
continues to impose its own dis-
integrative effect. . -
"The terraces of the palace
were much larger than what they
are today:' Hatzor says."There
have been failures and erosions
since Herod built it. We can see
deterioration of the stones due to
rain even in the time period we
have been involved in preserva-
tion efforts on the mountain?'
Work began in 1998, when
Israel's National Parks Service
began construction of a new cable
car to ferry greater numbers of
visitors up Wsada. They'called in
Hatzor to evaluate the mountain's
stability.
Hatzor and his team studied
the Snake Path cliff on the moun-
tain's eastern side, which connects
the cable car station to an adjoin-
ing bridge, and found several
large rocks precariously poised..
Using a three-dimensional stabil-
ity analysis, the team determined
that some blocks of rock in the
cliff face might dislodge even in a
relatively small tremor.
Hatzor suggested inserting
60-foot-long steel cables through
individual blocks and into the
solid rock, so the rock's own

JN

weight pushing against
the cables would act as a
stabilizing force.
An enormous yellow
rock hovers menacingly
over the walkway visitors
traverse on their way to
the ruins. Thirty anchors
were inserted into the
rock before the new cable
car was built. Rock-col-
ored covers hide the ends
of the anchors, preserv-
ing the aesthetics.
Hatzor's monitoring
system also showed, for
the first time, the effects
of climatic change on
rock movement.
After the cable car
project, Hatzor's team
was asked to study the
stability of Herod's pal-
ace on the northern side of the
mountain.
Using data from OA quake
in the northern Sinai in 1995,
Hatzor's simulation found that a
similar tremor at Masada could
cause shards of rock to come
crashing down the cliff.
"To ensure lasting preservation
of this historic gem, the north
face should be reinforced:' he
says, a project he estimates would
require several million dollars.
. Eitan Campbell, director of
Masada National Park, wants to
make sure that happens, even
though there is no budget for it
yet. .
Campbell has worked at
Masada for more than 30 years,
starting as a teenager. He hauled
bags of cement for archeologist
Yigal Yadin, who initially exca-
vated the site in the mid-1960s.
Two years of heavy winter rains

.•

_

Ben-Gurion University Professor Yossi Hatzor uses a monitoring
device to track seismic and climatic effects at Masada.

have caused significant damage
to the 2,000-year-old structures,
Campbell says. "The whole top of
the mountain was one big pool
of water. I've never seen anything
like it. A couple of the walls col-
lapsed?'
In mid-August, Glaser and
Hatzor will set up seismic moni-
toring stations at the visitors cen-
ter at the base of the mountain
and at the watchtower on 'top.
Gauges will measure the effects
of temperature, humidity, baro-
metric pressure and tidal pull on
the mouths of cracks. In addition,
the scientists will compare move-
ment at the mountain's base to
movement at its top.
The system has not been tried
anywhere else. "This will be its

field test:' Glaser says.
Restoration. of the palace is
already under way, thanks to an
Israeli government grant of $2.2
million. Campbell has had all the •
Roman frescoes from the lower
'part of the palace, the part most
susceptible to wind and rain,
removed. They are being restored,
and Campbell plans to mount
replicas in their place while dis-
playing the originals in a special
museum.
Visitor safety, however,is his
immediate concern.
Tourism slowed down consid-
erably after the Palestinian inti-
fada began in 2000, but has now
picked up. Half a Million visitors
came in 2005, and even more are
expected this year. ❑

