EERI Special Earthquake Report — March 2003

Learning from Earthquakes

Preliminary Observations on the Tecomán, , , Earthquake of January 21, 2003

This report is based on data collect- provided by the National Science ernment. The teams visited the ed after the earthquake by a num- Foundation under Grant 0321781. municipalities of Colima, Manzanillo, ber of teams and individuals. Four Financial support for the EERI team Tecomán, , Coquimatlán, separate reconnaissance groups and for the publication and distribu- Villa de Álvarez, Ixtlahuacan and collaborated in this effort, under the tion of this report was provided by the Armería (shown in Figure 1). recently signed cooperative agree- National Science Foundation grant ment between EERI and the Socie- #CMS-0131895 to EERI’s Learning As of February 20, the effects of the dad Mexicana de Ingenieria Sίsmica from Earthquakes Program. earthquake are as follows: 21 con- (SMIS). (See Acknowledgments for firmed dead; 500+ injured (this is a complete listing of team mem- Introduction an uncertain figure since there has bers.) The Earthquake Engineering not been a systematic confirmation On Tuesday January 21, at 8:06 p.m. Research Institute (EERI) team was of the injured); 13,493 residential local time, a strong earthquake shook headed by Richard E. Klingner of structures reported damaged (many the coastal region of the state of Co- the University of Texas at Austin. of these reports from rapid visual in- lima, Mexico. The earthquake was spections by public teams). Of the strongly felt in the states of Colima, The joint National Center for Disas- 13,493 structures, 11,009 had been and Michoacán. The effects ter Prevention (CENAPRED)/Mexi- inspected with the following official of the earthquake were also felt in can Society for Earthquake Engi- results: 2,728 total damage; 4,150 . The reported magnitude neering (SMIS) team was headed partial damage; 4,131 safe for occu- varies from M 7.4 (Harvard CMT) to by Sergio Alcocer of CENAPRED. w pancy. Six hundred structures hous- M 7.6 (USGS). The reconnaissance The joint Inter-University Seismic w ing medium and small businesses teams carried out a basic evaluation Research Group (GISS)/SMIS team also suffered some damage. The of the effects of the earthquake, con- was headed by Hugón Juárez Gar- military had established 56 disaster centrating on the response of struc- cía of Universidad Autónoma Metro- assistance centers to provide food, tures and soils, and also on the func- politana – Azcapotzalco. shelter, medical assistance, and tioning of response organizations in public information. different levels of the Mexican gov- The National Science Foundation (NSF)-sponsored geotechnical re- connaissance team was headed by Joseph Wartman of Drexel Univer- sity, Philadelphia, PA, and Adrian Rodriguez-Marek of Washington State University, Pullman, WA.

The EERI team arrived in Manzan- illo on January 23 and collaborated closely with the CENAPRED/SMIS team, which initiated reconnais- sance activities on January 22. The GIIS/SMIS team arrived in Colima on January 23 and visited damaged sites in the state of Colima as well as in the neighboring states of Jal- isco and Michoacán. The NSF team arrived on January 25 and coordi- nated with the EERI team already on the ground. Figure 1 - Epicentral locations of main shock and aftershocks as Financial support for the NSF geo- reported by the USGS and SSN. Included also is the epicentral technical reconnaissance team was location of the Mw 8.0 1995 Manzanillo earthquake.

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Seismicity can Plate, and the faster Cocos Ground Motions plate is moving in a similar direction Just as the initial reports on the at a rate of about 45 mm per year The Manzanillo Power plant record magnitude of the earthquake vary, (USGS http://neic.usgs.gov/neis/ is the only strong-motion record of so does the reported location of the bulletin/neic_phac.html). The earth- the earthquake obtained within 100 hypocenter. Table 1 lists the source quake was an interplate subduction km of the rupture plane. Various parameters of the event as reported event at the contact between the records at distances greater than by various agencies. Figure 1 plots North American plate with either the 120 km were obtained from strong the location of the epicenters as re- subducting Cocos or Rivera plates. motion arrays in and ported by various agencies, along Mexico City. The Manzanillo Power with the locations of aftershock epi- The event fi lled a seismic gap located Plant record registered maximum centers reported by the Servicio accelerations of 0.263g in the EW between the rupture zones of the Mw Sismológico Nacional de México 8.0 1995 Manzanillo earthquake and direction, 0.329g in the NS direction, (SSN). and 0.191g in the vertical direction. a Mw 7.6 earthquake in 1973 (Figure 2). A fault plane solution by Yagi Strong shaking lasted approximately The signifi cant discrepancies in (http://www.iisee.kenken.go.jp) 30 seconds. It was reported that moment magnitude and epicenter from the International Institute of earthquake movement ruptured the location obscure any preliminary Seismology and Earthquake Engi- power plant’s main 2.4 m diameter conclusions about the unusual dam- neering (IISEE), Tokyo, is shown in cooling water intake pipe, which age distribution. There was much Figure 3. The dimensions of the rup- caused the plant to operate at a re- greater damage to the inland city of ture plane are approximately 80 km x duced capacity in the days after the Colima than the coastal city of Man- 50 km. main event. zanillo (which is closer to the rup- ture zone as defi ned by aftershock hypocenters) while, in contrast,

damage from the 1995 Mw 8.0 Manzanillo earthquake was largely focused near the epicentral region.

The earthquake occurred near the juncture of three tectonic plates: the North American Plate to the north- east, the Rivera Plate to the north- west, and the Cocos Plate to the south. Both the Rivera Plate and the Cocos Plate are being subducted beneath the North American Plate. Figure 2 - Approximate location of rupture planes The slower-subducting Rivera Plate of subduction zone events since 1973 (http:// is moving northwest at about 20 mm www.ssn.unam.mx/Colima030121/index.html). per year relative to the North Ameri-

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Site Effects

Damage surveys in the conjoined cities of Colima and Villa de Álvar- ez indicated locations of damage concentration around the neighbor- hoods of San Isidro (Villa de Álvar- ez) and Lomas de Circunvalación (Colima) (see Figure 4). In addition, damage to adobe housing in down- town Colima was extensive. Dam- age surveys were carried out using PQuake software (Georgia Institute of Technology), which directly inte- grates digital photography and handheld GPS technology to facili- tate documenting, mapping, analyz- ing, and visualizing damage data. The use of PQuake permitted a digital data set of the earthquake Figure 3 - Fault plane solution by Dr. Y. Yagi (http:// effects to be created in a timely iisee.kenken.go.jp/staff/yagi/eq/colima/colima.html). manner. Damage surveys were per- formed either by assigning an aver- foundation material. Intense damage the coastal city of Manzanillo and in age damage index (D0 = no dam- in the Lomas de Circunvalación the neighboring cities of Villa de Ál- age, D5 = collapse) to a whole block neighborhood is limited to a few city varez and Colima, located approxi- (Block Survey), or by assigning blocks. Construction patterns do not mately 80 km inland. damage indices to individual build- vary in this neighborhood, suggesting ings. that damage is due to localized Liquefaction may have also oc- ground-motion amplification, suspect- curred in the sparsely inhabited re- The San Isidro neighborhood is lo- ed to be associated with fills. gion between these two urban cen- cated near the Arroyo de Pereira, a ters, though this was not confirmed small creek running north to south Soil Liquefaction during the reconnaissance. In Man- across Colima/Villa de Álvarez. zanillo, home to one of the largest Soil liquefaction caused damage in Most of the damaged area overlies highly heterogeneous fill. Evidences of liquefaction were found in areas of high damage concentration. Sig- nificant ground settlement was ob- served at some locations, possibly due to collapse of poorly compacted fills (Figure 5). There were numer- ous reports of open-pit sand mining earlier in the 1900s at this location. Poor filling of these pits could ex- plain localized zones of large sur- face settlement. Although construc- tion quality in the San Isidro neigh- borhood is poor, other neighbor- hoods with similar construction did not suffer as much damage.

The Lomas de Circunvalación neighborhood is underlain by vol- canic debris avalanche deposits that also underlie most of the north- central section of Colima. While this unit is highly heterogeneous, it is re- Figure 4 - Damage survey map of the city of Colima indicating areas portedly stiff and performs well as a of high damage concentration.

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Figure 5 - Large settlements in a house in the San Isidro neighborhood, possibly due to collapse of poorly consolidated fills.

ports in Mexico, liquefaction was A majority of the waterfront liquefac- settlement, and lateral spreading, largely confined to waterfront sites, tion sites in Manzanillo were marked alone or in combination, are sus- including multiple locations at the by lateral spreading of the ground pected causes of other damage to commercial shipping port, a public toward the free face. The horizontal the San Isidro neighborhood about walk near the center of town, and displacements varied between sites, 3 km northwest of the town center. a promenade located off a major but were often in the range of 1-3 m. Damage included uplifted, sunken, boulevard. Liquefaction-related Figure 6 shows lateral spread of a or cracked concrete floor slabs; damage at the port occurred prin- pedestrian promenade located off a cracked and distorted pavements cipally at undeveloped or non-criti- major boulevard. The promenade and sidewalks; and laterally dis- cal areas, and port operations surface consisted of paving blocks, placed residential structures. Por- were not significantly affected. whose positions after the earthquake tions of this neighborhood were clearly preserve the deformations reportedly built on reclaimed land During the 1995 earthquake, the caused by lateral spreading. Appar- adjacent to the Arroyo de Pereira, Port of Manzanillo suffered consid- ently, a 0.2-0.5 m thick crust of silty a small creek. Shallow subsurface erable damage due to liquefaction. sand moved over an unknown thick- materials at the site consisted of Since then, various ground-im- ness of liquefied ground. An over- uncompacted, miscellaneous fill. provement techniques (for exam- turned concrete railing is visible near Local residents reported that imme- ple, stone columns, vibro-compac- the right portion of the photograph. diately after the earthquake, muddy tion) have reportedly been used The ground slope was about 3%, and water was ejected from cracks in during repairs or new construction maximum lateral spread displace- pavement surfaces and damaged at the port to increase liquefaction ments at the site were on the order of concrete floor slabs. resistance of the ground at loca- 2 m. tions essential for daily operations. Figure 7 shows a concrete column It appeared that these improved Observed ground distortions (ground supporting a modern three-story sites generally performed well, with cracking with possible lateral spread- residential structure located in the no obvious liquefaction-related ing) in a residential district located Colima neighborhood damaged by ground-deformation features. Oth- about 3 km northeast of Manzanillo’s liquefaction. It is typical construction er areas of the port where ground city center suggest that liquefaction practice in Colima to support col- improvement had not been per- may have also occurred there, though umns and load-bearing walls on formed apparently suffered seismic this was not confirmed. This portion shallow foundations consisting of densification and lateral spreading. of town was reportedly underlain by spread and wall footings. During Quantitative assessment of the miscellaneous fill. the earthquake, the column experi- performance of these improved enced a loss of bearing capacity areas would provide valuable infor- In the city of Villa de Álvarez, just and dropped about 30 cm, causing mation about the efficacy of the northwest of Colima, liquefaction and significant structural damage to the ground improvement techniques. consequent loss of strength, ground building.

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Figure 6 - Liquefaction-induced lateral spread in Manzanillo (for scale, each paving block is 0.20 m square).

Landslides bedded with fluvial deposits. These material each. The continuing in- materials had little or no matrix ce- stability of these cliffs, exacerbated The earthquake triggered landslides mentation. by the ongoing removal of material estimated in the thousands. Classi- by falls, indicates a possible contin- fied according to the system of When this area was inspected on the uing hazard to villages, dwellings, Keefer (1984), the vast majority ground on January 28 and again on and other infrastructure in the areas were rock falls, rock slides, soil falls, January 31, the cliffs were so unsta- located close to the cliffs. and disrupted soil slides. Several ble that they were still producing sev- liquefaction-induced soil lateral eral falls each minute (Figure 9). On The other area of high landslide spreads were also observed, as January 31, in fact, 20 falls occurred concentration was along a 6-km was a single embankment failure in 15 minutes along a single section stretch of the Barranca de Atenqui- that has been classified as a coher- of cliff 1 km long, suggesting that ap- que watershed, a deep, steep-sided ent slide. proximately 2,000 falls were occur- canyon cut into the eastern flank of ring there each day. These falls were Nevado de Colima, an inactive vol- Two areas of particularly high land- typically small, ranging from a few cano. At this location, rock falls, slide concentrations were noted. cubic meters to perhaps 50 m3 of soil falls, rock slides, and debris The first is located along the steep walls of the Armería River canyon and along its tributary, the Remate River, north of Colima in the vicinity of the town of Zacualpan. Along each river, a stretch of 6-8 km was subjected to such intense landslid- ing that material was removed from stretches of slope hundreds of me- Figure 7 - Bearing- ters to more than a kilometer long in capacity failure in each of several localities (Figure 8). Colima. The column Most or all of these areas were on dropped through the the outside of meander bends. The floor of the structure, vegetated cliffs on which the land- ultimately settling slides occurred were typically 150- about 0.3 m. 200 m high and had slope inclina- tions estimated as ranging from about 70º to vertical. They were composed of very well-graded vol- canic debris-avalanche material, re- worked by fluvial action and inter-

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Figure 8 - Stretch of cliff along Rio Armería northwest of Colima denuded by landslides during the earthquake. Figure 9 - One of the larger falls observed Before the earthquake, this stretch of slope was reportedly from the Rio Armería cliffs on the afternoon vegetated in a manner similar to the intact stretch of slope of January 28, 2003, which had an estimated 3 at the extreme right of the photograph. volume of 20 m .

slides occurred in volcanic materials de Atenquique. The third area, along disrupted landslides were along arti- exposed on canyon walls, typically the lower valley of the Armería River ficial cuts. Fewer than 20 landslides consisting of an upper fine-grained near the coast, produced a moderate from natural, unaltered slopes were pyroclastic deposit, a middle unit number of landslides along highway observed outside those areas during consisting of well-indurated lava, and railroad cuts and along the bed- either aerial or ground-based recon- and a lower unit consisting of a py- rock valley walls. Outside of the areas naissance. The largest cut-slopes roclastic block-and-ash flow deposit discussed above, nearly all of the failures were along the Colima to (Figure 10). Volumes of the individu- al landslides typically ranged from a few m3 to a few hundreds of m3 each, and the highest landslide con- centrations were about 40 land- slides per linear kilometer of canyon wall. Slopes were near vertical and ranged up to about 500 m high. The landslides in this area damaged some irrigation systems.

Three smaller areas with moderate landslide concentrations were also observed. Two of these, on the south flank of Volcán de Fuego and along several smaller canyons south of the Barranca de Atenqui- que, evidently involved similar mat- Figure 10 - Landslides along one stretch of canyon wall in the Barranca de erials to those along the Barranca Atenquique, on the east flank of Nevado de Colima volcano.

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Minatitlán road, between the Armer- Reinforced Concrete Structures: In without mesh or mechanical anchor- ía River and the village of Platana- and around Colima, typical reinforced age. Masonry is typically laid in run- rillos. Cut-slope failures had report- concrete structures are at most four ning bond with no interlocking units edly blocked the main highway from stories high, probably because of re- between wythes. Bond beams are Colima to Manzanillo and the road quirements for installation of elevators generally not present at the level of from Colima to Minatitlán, but these in buildings with more floors. The the horizontal diaphragms, though blockages had been removed by level of ductile detailing is unknown. wood members were occasionally the time these areas were observed Stucco and tile facades are most used for this purpose. Lintels over during the reconnaissance. common, and are bonded to the un- openings are usually of wood, derlying structure by mortar without though sometimes masonry arches Structural Performance mechanical anchorage. The common are used. For single story houses, Damage to structures has been cat- practice is to place unreinforced ma- roofs are generally constructed of egorized according to construction sonry infills within bays of frames. tree trunks and small limbs. Addi- materials: steel; reinforced con- Typically, the infills are neither rein- tional wooden limbs are used to crete; confined masonry; unrein- forced nor connected mechanically support clay tiles or corrugated forced masonry; and adobe. Gener- to the surrounding frame. Overall metal or cardboard sheets. Roof ally, structural steel and reinforced damage to reinforced concrete struc- members are generally not attached concrete structures suffered little tures was minor. The most commonly to bond beams or the supporting damage, but had the earthquake observed damage consisted of minor walls. In larger houses, solid or pre- accelerations been greater, damage shear cracks in walls and columns fabricated reinforced concrete slabs to such structures could also have and spalling at beam-column connec- are used. The foundation is typical- been greater. tions. Most of these buildings were ly a continuous footing, with its base public facilities and therefore had about 0.4 m below grade, narrower Confined masonry structures suf- possibly been built with a higher level at the top than the bottom, consist- fered mostly minor damage, but of design and construction oversight. ing of large rocks interspersed with again, had the earthquake accelera- Most of these buildings appeared to small rocks and cement-sand mor- tions been greater, damage to such be repairable. tar. structures could also have been greater. Damage decreased as the Masonry Structures: Most masonry Confined Masonry — As common- number and size of confining ele- structures had solid units of fired clay, ly used in Latin America, confined ments increased, and also as the although a few used solid concrete masonry consists of unreinforced buildings’ configurations improved units (tabicón). Typical masonry struc- masonry panels, typically measuring (configuration issues are discussed tures were constructed with walls one 1-2 m in each direction, and joined below). to two wythes thick, with 20-100 mm by horizontal and vertical reinforced While damage to unreinforced ma- (1-4 in.) of mortar between courses. concrete elements that are poured sonry structures varied by location, Walls are plastered with approximate- in place after the masonry is laid in those areas of relatively heavy ly 30 mm (1 in.) of stucco on both (figure 11). Such confining elements damage, it was concentrated in faces, applied directly to the masonry generally are roughly square in structures of unreinforced masonry and adobe. Damage was largely due to inadequate connections be- tween walls and horizontal dia- phragms and between intersecting walls, and to collapse of walls under combined in- and out-of-plane loads.

Steel Structures: Only one steel structure was observed in Colima: a large storage area, half of which was covered by a roof supported by rolled steel shapes, and the other half, by large timber trusses. Due to an electrical short circuit after the earthquake, the timber half of the roof caught fire and collapsed. The portion supported by steel shapes Figure 11 - A typical confined masonry structure, which performed well in the appeared undamaged. Tecomán earthquake.

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Figure 12 - Typical damage to unreinforced masonry structures.

cross-section, with a cross-section- bined with inadequate out-of-plane the absence of reinforcement, such al dimension equal to the thickness strength due to a lack of reinforce- combined failure often led to col- of the masonry. They are generally ment; and in-plane shear failures lapse of walls and structures. Out- reinforced with four #3 (9 mm) bars occurred separately or in combination of-plane overturning of cantilever and transverse ties of heavy-gage with out-of-plane failure. Increases adobe walls was common. It is im- wire. Structural continuity between in in-plane stiffness and strength due portant to mention that the adobe masonry and confining elements is to stucco were lost as the stucco and unreinforced masonry houses generally obtained by mechanical spalled off due to lack of mechanical located in urban areas, damaged interlock between the running-bond anchorage. Due to the absence of or with partial or total collapses, are masonry and the cast-in-place con- reinforcement, combined in- and out- quite old, perhaps several decades. crete. Structures of confined ma- of-plane failure often led to collapse sonry performed better than those of walls and structures (Figure 12). Historical Monuments: The his- of unconfined masonry or adobe. torical monuments visited, mostly Cracks often formed between the Adobe Structures: Typical adobe churches, exhibited light damage, masonry and the confining ele- construction is very similar to that of such as spalling of stuccos and ments, the latter which sometimes unreinforced masonry. The foundation plasters, and damage to nonstruc- failed, but this was the case solely is typically constructed about 0.5 m tural elements. Fine cracks were when the number and arrangement below grade, and consists of large observed in walls, but such damage of confining elements was inade- rocks interspersed with smaller rocks does not compromise the stability of quate. In most instances, confined and mortar. Instead of a reinforced the structure. One exception was masonry structures remained concrete grade beam (as with unrein- the church of San Pedro in Coqui- unscathed. forced masonry), the adobe units are matlán, which suffered severe dam- laid directly on top of a layer of mortar age in the main part of the building, Unreinforced Masonry — Unrein- with no reinforcement or other fasten- as well as failure of the south bell forced masonry structures are con- ing method. Adobe structures com- tower, which collapsed onto the structed without horizontal or verti- monly have wooden lintels, and may yard of the municipal building. The cal confining elements. They may have wooden horizontal and vertical other tower showed damage in the have lintels of cast-in-place rein- confining elements. columns and permanent rotation forced concrete, but wood is more over one of the columns. The main commonly used. Their strength and In some locations, such as Villa de Ál- building showed severe shear initial stiffness may be increased by varez, damage to adobe structures damage in all walls and cupolas. stucco. These structures failed in was severe. As with unreinforced ma- The main cupola partially collapsed. two ways: walls failed out-of-plane sonry, it took the form of separation of Though the damage is severe, the due to lack of mechanical connec- walls from roof and floor diaphragms, structure is considered repairable. tion between the top of the wall and and in-plane shear cracking com- the roof or floor diaphragm, com- bined with failure out-of-plane. Due to Configuration: Independent of

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Figure 13 - Example of lack of structural continuity of vertical and horizontal elements.

material, structural performance was clearly enhanced by aspects of building configuration: presence and symmetrical location of shear walls; absence of large openings in street level walls; and continuity of vertical and horizontal elements (figure 13). Location within a block was also important. Corner build- Figure 14 - Typical damage to adobe structure at the corner of a block. ings appeared to suffer relatively heavy damage, due to a combina- Support provided by the National rescue groups. After the earthquake, tion of the effects of openings in Center for Disaster Prevention those groups met almost daily to walls, and the plan eccentricity be- (CENAPRED); and the National Fund coordinate their efforts (Figure 16). tween the center of mass (generally for Natural Disasters (FONDEN), located near the plan center of the which provides the funds required to The emergency response to the building) and the center of rigidity finance emergency response and re- January 21 earthquake was appar- (generally located near the interior covery operations. The system relies ently rapid and well-managed by the corner of the building plan). This heavily on the resources of all levels State of Colima’s Civil Protection

plan eccentricity led to heavy dam- of government, academic institutions, System. The Mw 7.6 event did not age in the shear-resisting elements nongovernmental organizations such cause the level of damage that could on the corner façade of the build- as the Mexican Red Cross, and a have been expected. It killed 21 ing, and sometimes to collapse of wide range of volunteers such as people, mainly in adobe structures, the exterior walls near the corner those from the Colleges of Architects including 14 who died in Colima (Figure 14). and Engineers, the Construction from the collapse of their houses. Industry Chamber, and search and Four others died in hospitals from Emergency Response The organizational relationships among the different groups partici- pating in the emergency response are presented graphically in Figure 15. One of the primary purposes of the National System of Civil Protec- tion (NSCP) is to coordinate the governmental and volunteer emer- gency response and recovery oper- ations during disasters. The Secre- tary of Government is responsible for the NSCP. At the national level, the system is composed of three main elements: Emergency Opera- tions (General Direction of Civil Figure 15 - Approximate organizational relationship Protection); Scientific and Technical among groups involved in disaster recovery.

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Figure 16 - Representatives of the government, academic institutions, and non-gov- ernmental organizations met almost daily to coordinate their efforts.

injuries in Colima, and three from in- magnitude earthquakes in the past the owners of homes or businesses juries elsewhere, a relatively low century. According to Civil Protection that were damaged, since they are mortality rate for such a large earth- authorities, much has been learned unsure about the safety of their quake. from these events, and significant structures and whether they could progress has been made in improving continue to be occupied. While the earthquake damaged un- building codes and practices. reinforced masonry structures and As of February 11, there were only some low-quality concrete frame There is a strong military presence in 95 volunteer inspectors in the field, buildings, it caused no major col- the city of Colima, with many types of organized and trained by the Col- lapses of engineered buildings, and resources that have been deployed to leges (associations) of Architects only slight-to-moderate damage to assist the civilian efforts. Thus far, and Engineers and the Chamber of roads, potable water, electrical pow- the military has provided shelter and the Construction Industry. The data er, and communication systems. the personnel and equipment for de- they are collecting is being categor- The demand for search and rescue molition and debris removal. Be- ized by “total damage,” “partial dam- resources was minimal, and the cause the city of Colima is the capital age,” and “slight damage.” The rapid medical system was able to treat of the state, all of its resources were visual assessments provide the ba- the injured within hours after the readily available to assist the affected sis for determining which structures strong shaking ceased. municipalities. will require a more detailed assess- ment, be designated for demolition, The readiness and competency of Disaster Recovery or be repaired. This is an area responders can be attributed to a where the utilization of GIS, such as number of factors. The Colima Vol- Only five days after the earthquake, that used by the EERI team, could cano has been active for many the initial recovery from the disaster dramatically increase productivity years, and the State Civil Protection was well underway, being supported and efficiency. has often had to evacuate towns lo- by the all levels of government, the cated in the most hazardous areas. private sector, and the affected popu- The Civil Protection System asked The frequent activation of the sys- lation. At the time of the visit, the the Mexican military to begin the tem has provided the agencies and most important issue was the need to demolition of structures categorized their personnel with practical emer- continue with the safety inspection of as totally damaged and to remove gency response experience. Fur- damaged structures. In some towns the debris from streets. The team thermore, the State Civil Protection in the outlying areas, practically every observed the demolition of damaged System has been active in forming adobe structure suffered some kind adobe structures in the Municipality and training specialized teams to of damage, and some people were of Villa de Álvarez, which borders respond to multiple hazards includ- still occupying structures that were the northwest section of the city ing floods and hurricanes. Colima severely damaged. This situation of Colima (Figure 17). After the has also experienced several large- caused concern, especially among demolition in that area is complete,

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The financing of this disaster will pose some major challenges to the federal government. The mech- anisms used by Mexico to finance disaster recovery are complex and can at times be problematic. For example, in other times, the 144.7 million pesos committed to disaster recovery would have been diverted from the federal fiscal year 2003 budgets of the key agencies in- volved in promoting socioeconomic development. This diversion of re- sources would run the risk of retard- ing progress in this most important national priority. In recognition of this serious problem, the federal government instituted FONDEN (Fund for Natural Disasters) in 1996 and allocates a fixed annual amount (in 2003, FONDEN’s budget is ap- proximately US$350 million) to fi- Figure 17 - Demolition by the Mexican military of adobe structures catego- nance the repair or replacement of rized as totally damaged. uninsured public facilities, and to provide disaster assistance to the large parcels of adjacent vacant housing units; 79.7 million pesos for poorest sectors of the affected pop- land will be left behind. It is difficult assistance to the private sector, pri- ulation. to discern at this time whether the marily small businesses; 20 million municipality will prohibit rebuilding pesos to assist those unemployed In recent disasters, the FONDEN in that area. due to the disaster; and 3 million has been able to restore the funds diverted from other federal agen- Immediately after the earthquake, pesos to promote tourism. This is only cies, but there have been other the Governor of Colima ordered all the initial installment, but it is deemed times when a few major disasters schools to close for the rest of the enough to move the recovery forward have driven FONDEN into insolven- week to allow time for safety inspec- and stimulate the recovery of the cy before the fiscal year was over, tions. Of the 703 primary and sec- state’s economy. More importantly, and agency funds were not re- ondary schools in the state of Coli- these actions are an effort to distri- stored. ma, according to initial reports, 220 bute funds to those in need as quickly suffered some level of damage (fig- as possible. The FONDEN is a unique approach ures 18 and 19). All schools were scheduled to open on Monday, Jan- uary 27, 2003. Students from damaged schools were to continue classroom instruction in temporary safe facilities.

The direct economic impacts of the disaster are beginning to emerge, but remain somewhat murky due to the discrepancies among the esti- mates being provided by various federal, state and municipal sources. Nevertheless, the federal government has already committed to provide 144.7 million pesos (ap- proximately US$14 million) to be used for funding a variety of recov- ery programs: 42 million pesos for the repair or rebuilding of damaged Figure 18 - Damage to a school building.

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Macrosismo de Manzanillo del 9 de octubre de 1995. ISBN 968- 6190-83-X, Sept. 343 pp

Figure 19 - Inclined cracking in an infill wall of a school building in the village of Ixtlahaucan. The structure of the school is made of light gage steel members.

to financing disasters. Some as- Jara of Universidad Mich- pects of FONDEN are innovative oacana San Nicolás de . and may be of some interest to the United States. This disaster may In addition to Wartman and Rodri- provide opportunities for knowledge guez-Marek, the NSF team included transfer between the United States David Keefer of the United States and Mexico, and how the FONDEN Geologic Survey, Menlo Park, CA; is applied in this disaster may merit Scott Deaton of the Georgia Institute further study. of Technology, Atlanta; Pedro Repet- to, URS Corporation, Denver, CO; Emir Jose Macari, Louisiana State Reconnaissance Team University, Baton Rouge; and Carlos Members Navarro Ochoa, Juan de la Cruz In addition to Richard Klingner, the Tejeda Jacome, Carlos E. Silva EERI team included Paul J. Flores Echartea and José Armando Téllez of ABS Consulting, , Alatorre of the Universidad de CA; and Anna F. Lang of Tipping Colima, Colima, Mexico. Mar & Associates, Berkeley, CA. David Frost and Scott Deaton (Geor- In addition to Sergio Alcocer, the gia Institute of Technology and Data- CENAPRED/SMIS team included forensics, Atlanta, GA) provided the Roberto Durán Hernández, Leonar- software PQUAKE, which was used do Flores Corona, and Carlos to record and organize data during Reyes Salinas, all of CENAPRED. the geotechnical reconnaissance.

In addition to Hugón Juárez García, References the GISS/SMIS team included Emilio Sordo Zabay, José Juan Keefer, D. K. (1984). “Landslides Guerrero Correa, Mario S. Ramírez caused by earthquakes.” Geological Centeno, Alonso Gómez Bernal, Society of America Bulletin, v. 95, pp. Tiziano Perea Olvera, and Eduardo 406-421. Arellano Méndez of Universidad Autónoma Metropolitana - Azcapot- Singh, S. K., and J. F. Pacheco zalco; Rafael Martín del Campo of (1994). “Magnitude determination Instituto Tecnológico de Estudios of Mexican earthquakes.” Geofisica Superiores de Occidente; Horacio Internacional, v. 33, pp. 189-198. Ramírez de Alba, Raúl Vera No- guez, and Sandra Miranda Navarro Sociedad Mexicana de of Universidad Autónoma del Esta- Ingeniería Sísmica y Universidad do de México; and José Manuel de Colima, México (1997). El

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