2010+Haiti+Earthquake


 * 2010 Haiti Earthquake (January 12, 2010) **

// Kyle S. Wagner, BAE/MAE, Penn State, 2010 //

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Introduction
On January 12, 2010, a 7.0 magnitude earthquake struck Haiti, the poorest country in the western hemisphere. The Caribbean nation, already crippled by widespread poverty, was devastated by the earthquake, which caused structural collapses and failures all across the region. It is estimated that the death toll exceeded 220,000, with the number injured nearing 300,000 (EERI 2, 2010). Although a seismic fault does run through the region, there had not been a large earthquake there since 1770 (Fierro, 2010). This left the people of Haiti much more concerned about hunger and starvation, as well as the constant threat of hurricanes, than about any imminent quakes. The result of these factors was a region with poor construction materials and methods, uneducated builders, inadequate response plans, and citizens who were ignorant of the seismic threat. Ultimately, this created a level of destruction that would not have occurred in other, less impoverished, parts of the world.

Earthquake Overview
The majority of Haiti lies along a fault which represents the boundary between the Gonave microplate to the north and the Caribbean plate to the south. The fault is a strike-slip fault where the plates move past each other horizontally. The strains slowly develop between the plates over time and eventually cause these types of large earthquakes. It was initially believed that the earthquake originated from the Enriquillo fault. GPS measurements of the area have estimated that the strain of this fault is around 7mm per year. After nearly 240 years of inactivity, nearly 1.7 m of strain had accumulated. According to several prominent geologists, this meant the region was overdue for around a 7.0 magnitude earthquake (Mann, 2010). Upon further geological investigation of the fault area after the earthquake, no surface rupture was found along the Enriquillo fault and GPS data seemed to suggest that this fault was not the source. It was determined that a previously unknown fault, deemed the Leogane fault, triggered the earthquake in Haiti, and the Enriquillo fault may still be poised to deliver an additional earthquake to the region (Gardner, 2010).

The 7.0 magnitude earthquake struck a heavily populated area near the Haitian capital city of Port-au-Prince. The epicenter was located just 15 miles west of the city. The shallow quake occurred only 8.1 miles beneath the surface and caused significant structural damage in Port-au-Prince and the surrounding cities (Magnitude 7.0, 2010). Many of the structures built in the region were built on soft soil, which works to amplify the seismic forces on structures. Based on observations of the damage around the area, it was estimated that the peak ground acceleration was around 0.45g and possibly higher, althought no instruments were present to obtain actual ground motion data (Fierro, 2010). Violent shaking was felt across the country, leaving millions exposed to the dangers of such a substantial earthquake.

Haiti Background
In many parts of the world, this earthquake would have been much less dangerous than it turned out to be in Haiti. This is primarily due to the substantial poverty in the affected region. Haiti is the poorest country in the Western Hemisphere and consistantly ranks among the lowest countries in the world on the Human Development Index. This poverty caused extensive shortcomings with regard to the building materials and methods in the region. The average citizen was much more worried about hunger and starvation than they were about a large earthquake, which hadn’t occurred there since 1770. The 1770 earthquake was a violent precursor, in which the “whole city collapsed” as quoted by a French historian (Fierro, 2010). The region was historically a dangerous seismic region, yet no one seemed concerned due to the long period since the last quake.

The people of Haiti, along with the emergency response teams and infrastructure, were all significantly unprepared for what occurred there. This lack of preparedness was largely due to the fact that the people had more immediate worries than earthquakes. A major earthquake had not occurred in the lifetimes of the people. Significant hunger and poverty were more pressing issues. Additionally, Haiti lies in a very hurricane prone region. Builders were concerned about resistance to hurricane forces, leading to heavy masonry and concrete structures to withstand the heavy winds. The vulnerability to hurricanes was made evident in the summer of 2008 when hurricanes Gustav, Hanna, and Ike caused destruction in Haiti killing 800 and leaving around a million homeless. This focus on hurricanes and hunger for the average person was understandable, yet it left them uneducated and unprepared in terms of earthquake preparation.

Damage Assessment
Construction methods throughout the country included a wide variety of building types and complexity. Structures ranged from small residential housing units made of wood and corrugated metal to larger, multi-story concrete structures. As would be expected, the former seemed to fare better than the latter in this case. Smaller residential structures utilizing metal roofs seemed to suffer less damage when compared to larger multi-story concrete structures. Throughout the country, a handful of well constructed structures survived the earthquake successfully. The U.S. Embassy was one of these, suffering only minor damage (Mw, 2010). Unfortunately, this was not the case throughout the rest of the country, where acceptable construction quality seemed to be the exception, rather than the rule.

It was reported in late January that 20,000 commercial structures and 225,000 residences had been destroyed by the earthquake (Fierro, 2010). Concrete and masonry structures, which made up the vast majority of the structures throughout the country, proved to be too brittle and weak to withstand the applied lateral forces. This resulted in widespread failures throughout the country.

Upon assessment of the damage throughout Haiti, many of the same issues seemed to reappear in nearly all of the structural failures. One issue that caused widespread failures during this event was the lack of proper reinforcing in the concrete, that is, if reinforcing was provided at all. Concrete tends to perform very well under compressive forces like gravity, but very poorly under tensile loading. Proper rebar is required to handle the tensile forces on a structure like those induced by an earthquake. In many cases, smooth bars were used instead of corrugated bars, providing an insufficient bond with the concrete. Additionally, there were many instances where structures lacked proper rebar ties, or ties lacked the proper hooks to provide confinement during a seismic event. Often times, hoops were not provided at the beam column joint. Despite being the site of the largest seismic forces, the beam column joint was the site of other construction mistakes as well. Column bars were often spliced within the joint, and beam bars often terminated at the face of the joint. This left one of the most critical locations of the structure very vulnerable to failure.

Another issue that became evident during the reconnaissance was the poor quality construction materials. The concrete used in these structures did not have the required amount of cement to create a strong mixture. This led to weak concrete being common throughout the region. To make matters worse, corrosive materials such as local beach sands were used in the concrete as well.

The single quality of these structures that made them resistant to hurricanes, their large mass, also made them extremely susceptible to earthquake failure. The widespread use of unreinforced masonry infill walls increased the building mass, as well as the inertial forces applied to the structure during seismic loading. These forces proved too much for the subpar Haitian structures to handle.



It became clear that even the most critical structures had experienced failures. Government buildings, hospitals, and critical ports were several of many critical structures to experience failure. Even the National Palace, a building thought to be among the most earthquake resistant in the country, had collapsed (Joyce, 2010). This left no place to perform surgery on the injured survivors, hampered efforts to bring aid to the country, and left behind a sense that no one from the government was in charge.

Factors Contributing to the Disaster
The extreme poverty in the region, and the lack of proper education regarding its dangerous seismic past, caused the Haitian people significant issues with regard to seismic preparation. The building methods used were extremely improper and dangerous for the occupants inside.

The first mistake in terms of construction of structures was the lack of building codes and licensing requirements in the region. Under normal conditions, poor and impoverished countries tend to adopt an international building code from America or Europe and enforce that code throughout the region. This was not the case in Haiti. Not only did they not have their own codes, but they also failed to adopt an international code or use codes of any kind. The majority of structures were either constructed by the homeowners themselves or by inexperienced contractors, and corners were often cut in an effort to save money (Booth, 2010). This left structures with improper, cheap materials and sloppy construction methods. There were no building inspectors or codes to combat this trend. These practices occurred over many generations and left thousands of structures that were dangerously constructed.

Building materials were commonly compromised in an effort by the builders to save money on the structures. Concrete mixes were used with improper aggregate and weak cement or mixed with salty sand or dirty materials, resulting in concrete that was not strong enough. Also, adequate amounts of reinforcing bars were not utilized in the structures. This resulted in walls crumbling and cracking during earthquakes because there were inconsequential amounts of rebar to withstand the tensile forces (Barnes, 2010).

Construction methods suffered in addition to the building materials themselves. Builders were not educated about seismic design, causing them to make significant errors during construction. There was no effort to provide the seismic detailing that was required, and significant mistakes were made including the lapping of rebar at the joints between the floors and columns of a structure, an area where seismic forces are at their maximum.

Preventative Solutions
A building code for the region is absolutely essential. It is fairly clear that the development of a national code for the country of Haiti is unlikely, due to the poverty that is predominant. It is more likely that an already developed, international code would be adopted for the region. Proper inspection and inforcement of this code would be necessary as well.

In addition to the adoption of a new code, it is important that the local builders are educated about what is expected of them. It is essential to provide some form of media (pamphlets, diagrams) to provide basic education with regards to how to provide proper seismic detailing and reinforcing. This is crucial. As this process is occurring, code officials must be put in place to enforce the government codes and verify that the builders are constructing structures that are adequate and safe.

It would also be beneficial to implement some sort of prefabricated construction plans for the country as well. This might be an effective solution to the issue of quality control with respect to construction in the region. Prefabricated residential housing units could be imported, along with precast concrete to be used in larger structures. The large amounts of foreign investment in the region could be used to put these plans into action in order to make Haiti safer in the future.



The officials in Haiti need to rethink and reevaluate the emergency response and infrastructure systems that are in place there. This earthquake has been proof that the current systems are grossly inadequate. The structural failure of schools, hospitals, roads, government buildings, and crucial ports that occurred in the earthquake is unacceptable. The failure of local teams to respond, even days later, is intolerable. These are the items that have to be better in the event of another earthquake. Careful seismic design of critical structures must occur, along with the proper training, equipping, and education of emergency responders.

It is clear from the 1994 earthquake in Northridge, CA, that these steps can be successfully implemented and beneficial. The Northridge earthquake was a 6.7, approximately the same magnitude as the Haiti event, was around the same depth, and struck an area of similar population density. This earthquake showed that the proper seismic codes, and the enforcement of these codes, can save many lives. Only 61 people lost their lives in Northridge, while around 220,000 died in Haiti. It is essential that these changes occur quickly, in order to keep this event from ever happening again.

Additional information about the Northridge Earthquake is available here.

Aftermath
In the days and weeks following the disaster in Haiti, a worldwide outpouring of support occurred for the victims. Aid flowed in from countries around the world in an attempt to prevent further deaths in Haiti. The emergency response provided food and temporary shelter for millions of Haitians. However, after the immediate danger subsided, the real problems began.



With billions in aid pledged from around the world, the task became how to properly rebuild the country with a long term focus. This meant planning basic infrastructure, which had not even existed prior to the earthquake. It meant the establishment of proper land ownership rules as well. This was not an easy task given the fact that the government was in shambles after the earthquake, having lost nearly a third of all its employees. Additionally, many of the donor nations have requested the establishment of mechanisms to prevent corruption and waste in Haiti. This has also been a slow process. By the end of the year in 2010, very little of the original aid money will have been spent rebuilding the country (Booth, Sheridan, 2010).



In comparison to many other government ventures, the financial aid process in Haiti has been incredibly fast; although that offers little comfort to those Haitians who are still homeless. Cholera has spread throughout the region, officially resulting in 1,800 deaths and around 81,000 infected. Unofficially, it is thought that the actual numbers may be twice that. Although Cholera has a mortality rate of less than 1.5 percent among those treated, there are simply not enough physicians in the area to treat the sick. In the city of Maissade, there are only two physicians for a population of 60,000 Haitians. Haitians in rural areas of the country are often unable to reach the cities for treatment. It is estimated that the Cholera situation is worsening in the region, and will continue to worsen over the next few months (Associated, 2010).

Chile Earthquake Comparison
In stark contrast to the Haiti earthquake, was the earthquake that occurred in Chile at the start of 2010. The earthquake in Chile occurred just off the coast of that country. It was felt by nearly 80% of the country’s residents. The epicenter was located 65 miles from Concepcion, the nation’s second largest city. The epicenter was close to Chile’s 1960 Valdivia earthquake, which was a 9.5 magnitude event, the largest ever recorded (Magnitude 8.8, 2010).

The recent earthquake in Chile was an 8.8 magnitude rating on the Richter Scale, nearly 500 times the magnitude of the 7.0 earthquake in Haiti (Reuben, 2010). Despite the significantly larger scale, the response in Chile was radically better. Damage did occur throughout Chile due to the earthquake. Some buildings fell over, and many experienced damage. The location of the earthquake just offshore produced a tsunami that caused even more damage throughout the coastal areas. Despite this, the loss of life in this event was limited to around 500 people (Magnitude 8.8, 2010).

The immense success in protecting lives in Chile was largely due to the quality of structures that exist throughout the country. Chile had learned from their experience with the 1960 Valdivia earthquake, and went on to develop substantial code restrictions and limitations with regard to seismic design. These code standards and building officials lead to the production of safe, well designed structures in the event of a seismic occurrence. A focus on dissipation of seismic energy in a safe manner, along with keeping the structures’ columns intact was crucial in these designs. This quality is well evident upon comparison with the earthquake in Haiti (Reuben, 2010).

Additionally, the emergency response in Chile was remarkable. Shortly after the earthquake, emergency responders were out rescuing survivors from the rubble. This undoubtedly saved a significant number of lives. Unfortunately, this was not the case in Haiti, where the responders were unprepared and unequipped for what occurred.

The Haiti earthquake proved what can happen when seismic threats are neglected and ignored. It is unfortunate that the disaster in Haiti occurred; yet, it is critical that it be seen as a learning experience, and not repeated. The Chile earthquake can be viewed as a roadmap as to how to save significant lives in the future.