Geotechnical Report from June 23, 2001 Peruvian Earthquake

3.0 RECONNAISSANCE FLIGHT

A Piper Cheyenne III Aircraft was used in a reconnaissance flight of the area affected by the earthquake. The flight departed from Lima and finished in the city of Tacna, in the southern edge of Peru. A refueling stop in Arequipa was necessary. The flight course was selected to cover areas where damage was reported and is illustrated in Figure 3.1. The flight altitude over affected areas varied between 1000 and 3000 feet depending on the topography of the region. A GPS unit was used to track the aircraft position. The time in the digital cameras was synchronized to the GPS unit to provide an accurate location of each photograph. Low coastal fog did not allow reconnaissance of the coastal towns. Observations from the reconnaissance flight are summarized with pictures corresponding to the four separate regions identified in Figure 3.1.

map: Flight course of the July 8 reconnaissance flight

Figure 3.1: Flight course of the July 8 reconnaissance flight. The base map was obtained from the USGS website (http://earthquake.usgs.gov/). The epicenter of the aftershocks up to July 7 is shown to provide an approximated location of the rupture plane. Photographs from the identified regions (one through four) are shown below.

Region 1: Rata Luchea

landslide observed in road cuts in the Rata  Luchea region

Figure 3.2: Typical landslide observed in road cuts in the Rata Luchea region. The road is currently being cleared by construction equipment. No apparent damage was observed from the air in the small towns in this region.

Region 2: Arequipa

Aerial view of the Cathedral in Arequipa showing damage to the bell towers

Figure 3.3: Aerial view of the Cathedral in Arequipa showing damage to the bell towers. Observe that no other significant damage is apparent in the photograph in buildings surrounding the cathedral. In general, relatively little damage was seen from the air in the city of Arequipa.

Region 3: Moquegua and vicinity

Typical damage to adobe construction in the city of Moquegua

Figure 3.4: Typical damage to adobe construction in the city of Moquegua. Many of the damaged buildings have been removed.

Region 4: Tacna

Aerial view of the city of Tacna

Figure 3.5: Aerial view of the city of Tacna. Typical constructions in these and other cities in southern Peru are two-story brick and reinforced concrete structures that are left with columns for future construction of the third story. This creates difficulties for the identification of damaged buildings from the air.