Nov 22, 2010 by  Larry O’Hanlon  (see article here)

Two large earthquake faults could expose the Panama Canal to serious shaking and perhaps damage, say geologists who have uncovered 1,400 years of fault ruptures in the area.  The threat comes from the Limon and Pedro Miguel faults in Central Panama which have ruptured both together and separately in the past.

A team of seismologists sorted out the history of the past quakes by deciphering extensive changes in the landscape — like streams offset several feet or meters — and shifts in at least one historical road. The analysis on the seismic history and hazards of central Panama was published in the latest issue of the Bulletin of the Seismological Society of America. The study was done at the behest of the Panama Canal Authority, which is in the process of expanding and upgrading the canal so it can handle much larger ships carrying far more cargo.

“An earthquake (in 1621) offset the Camino de Cruces that the Spanish used to get gold to Panama City,” said Thomas Rockwell of San Diego State University. The centuries-old cobblestone road was cut by one of the faults and offset about 10 feet. A similar sort of offset could cross the canal itself.  Paleoseismic investigations by Rockwell and his colleagues show that both the Limon and Pedro Miguel faults are active, recur frequently with large quakes and can shift the ground from 1.5 to 3 meters (4.9 to 9.8 feet).

“There was a general perception before this (study) that there weren’t any earthquakes (in the Panama Canal area),” said Rockwell.   Geologically speaking, there is every reason to expect earthquakes in Panama, since the land there was created by the ongoing collision of tectonic plates, Rockwell explained. The new assessment will likely be used in the design of the new canal locks.

 But what really worried Rockwell and other seismologists is Panama City and the large lake, Lago Gatun, in the middle of the isthmus, which is held back by two aging dams.  “This is a very real issue,” said seismologist Mary Lou Zoback. “There have been hints at this (quake history and threat) but we hadn’t a comprehensive picture. I’m quite honestly much more concerned about Panama City. It is a very large fault and has a potential for a very large earthquake.”  Panama’s population is about 3.3 million. About 1.2 million of those people live in Panama City, Zoback pointed out.

 Many live in homes made with heavy, un-reinforced blocks on steep hillsides that could easily collapse in a strong earthquake, she said.  Then there is the huge Lago Gatun, which supplies the water to the locks that make the canal function.
“The real concern is if you breach one of the dams and drain the lake, it would take 10 years to refill it,” said Rockwell.

 “So it’s not just a matter of repairing. This would ruin Panama’s economy.” (and impact martime transport and the world’s economy as well!!)

ABSTRACT OF THE PUBLICATION:

We present new geologic, tectonic geomorphic, and geochronologic data on the slip rate, timing, and size of past surface ruptures for the right-lateral Limón and Pedro Miguel faults in central Panamá. These faults are part of a system of conjugate faults that accommodate the internal deformation of Panamá resulting from the ongoing collision of Central and South America. There have been at least three surface ruptures on the Limón fault in the past 950-1400 years, with the most recent during the past 365 years. Displacement in this young event is at least 1.2 m (based on trenching) and may be 1.6-2 m (based on small channel offsets). Awell-preserved 4.2 m offset suggests that the penultimate event also sustained significant displacement. The Holocene slip rate has averaged about 6 mm=yr, based on a 30-m offset terrace riser incised into a 5-ka abandoned channel.  The Pedro Miguel fault has sustained three surface ruptures in the past 1600 years, the most recent being the 2 May 1621 earthquake that partially destroyed Panamá Viejo. At least 2.1 m of slip occurred in this event near the Canal, with geomorphic offsets suggesting 2.5-3 m. The historic Camino de Cruces is offset 2.8 m, indicating multimeter displacement over at least 20 km of fault length. Channel offsets of 100 –400 m, together with a climate-induced incision model, suggest a Late Quaternary slip rate of about 5 mm=yr, which is consistent with the paleoseismic results. Comparison of the timing of surface ruptures between the Limón and Pedro Miguel faults suggests that large earthquakes may rupture both faults with 2-3 m of displacement for over 40 km, such as are likely in earthquakes in the M 7 range. Altogether, our observations indicate that the Limón and Pedro Miguel faults represent a significant seismic hazard to central Panamá and, specifically, to the Canal and Panamá City. (complete report here)

Limon and Pedro Miguel Faults and the Panama Canal

Camino de cruces shift

Stone pavement of Camino de Cruces

PANAMA CITY, Panama – The President of the Inter-American Development Bank, Luis Alberto Moreno, and the Minister of Economy and Finance of Panama, Frank De Lima, participated in a ceremony to officially announce that the 54th Annual Meeting of the Board of Governors of the IDB will take place in Panama City March 14-17, 2013.

“It gives me great pleasure that Panama will host our next Annual Meeting,” said President Moreno. “I cannot imagine a more propitious meeting site,” he added. “Panama is amongthe region’s countries with the greatest potential for economic expansion in the next decade, in addition to its bid to become the Hub of the Americasin 2020.”

The IDB Annual Meeting draws more than 3,000 participants, including ministers of economy and finance, central bank presidents, and other senior economic officials of the Bank’s 48 member countries. Also attending will be directors of private companies and representatives of aid and development agencies.

“Without a doubt, this is one of the most important international events to be held in our country,” said De Lima. “This meeting will give us the opportunity to make an important and responsible contribution to discussions of issues of great importance to the development of Latin American and Caribbean countries and relationships among them.

The meeting provides the opportunity for government officials to discuss IDBoperations and institutional priorities as well as the region’s challenges and development needs.

In addition, a series of seminars will be held during the meeting to address issues such as biodiversity, logistics, maternal and child health in Mesoamerica, and the use of broadband to foster growth and social inclusion. There will also seminars on the role of the private sector as a partner in the region’s development and youth and social innovation.

In conjunction with the meeting’s official opening on March 14, senior business executives will participate in a Mesoamerican Business Summit. (original article)