UMW Regional GeogBlog

Updated January 14, 6 am.

I am writing these words less than 24 hours after the disastrous January 12 earthquake struck near Port-au-Prince in Haiti.  I have CNN on in front of me, and it seems to that despite the non-stop coverage of the disaster, nobody really knows what is going on, how many people have lost their lives, or how many have been injured. But what is clear is that this is a disaster of epic proportions, and that its human impact will be at least as severe as the 2008 Sichuan earthquake, and possibly even as profound as that of the 2004 Indian Ocean tsunami.

In order to understand the impact of this earthquake, though, we need to go beyond the live reports and graphic photographs, and ask why this  earthquake in this place has been so devastating. It was a powerful quake, to be sure, but other quakes as or even more more powerful than this have done less damage and killed fewer people. The answer to this question lies in the physical and human geography of Haiti.

The Physical Geography of the Earthquake

To understand the Haiti earthquake and its consequences, we first need to ask why the earthquake (and its powerful aftershocks) occurred here rather than anywhere else. The answer to this question can be found by examining the structure of the earth, and in particular the geographic configuration of the earth’s tectonic plates.

Most earthquakes are caused by movement along the boundaries of the massive slabs of rock called tectonic plates that make up the crust of the earth. Yesterday’s Haiti earthquake was caused by movement at the boundary of the Caribbean and North American plates. In this area, the Caribbean plate is moving eastward with respect to the north American plate at an average speed of about 20 mm per year. This movement doesn’t take place smoothly, but rather in a series of jolts, which can produce earthquakes of varying sizes. In the area where yesterday’s quake occurred, there had been little movement for 250 years, according to a British geologist. “It’s been gathering stress all that time as the plates move past each other, and it was really just a matter of time before it released all that energy. The question was going to be whether it would release it all at once or in a series of smaller earthquakes,” he told the BBC.

Yesterday’s quake had a magnitude of 7.0 (this is a measure of the amount of energy released by the quake,) and was followed by numerous aftershocks, many of them with magnitudes of over 5.0.

Earthquakes can take place at various depths below the surface, and be caused by either vertical or horizontal movement of rock (or a combination of both.) The Haiti quake was caused by horizontal movement, and took place at a depth of about 10km below the surface. This is a relatively shallow earthquake, and its shallowness contruibuted to its devastating power (earthquakes that take place deep below the surface tend to cause less damage, since the rock between the quake and the surface acts as a buffer, absorbing some of the quake’s energy.)

The topography of the area affected by the quake appears also to have contributed to the devastation. Many of the of  Port-au-Prince’s residential area have been built on hillsides surrounding the city, and early photographs of the damage show that many homes appear to have tumbled down the slopes under the force of the quake (see below.)

Physical geography has been unkind to Haiti not just in terms of seismic activity. The country also lies in the path of North Atlantic hurricanes and tropical storms. In 2008, four such storms hit the country, causing widespread damage and the loss of several hundred lives. early a tenth of the country’s population needed humanitarian assistance as a result of the storms.The effect of storms in Haiti is exacerbated by the fact that most of the country’s trees have been cut down to make charcoal, which is used, particularly in the poorest households,  for cooking. Today, only 3 percent of the country’s original forests remain.  Deforestation, by removing the natural ‘sponge’ that absorbs rainfall, means that storms would otherwise have done little harm now cause floods and landslides.

The Human Geography of Haiti

Population Geography. Not all earthquakes cause disasters. In fact, not even all powerful earthquakes cause disasters. If a quake takes place in an unpopulated area it may cause little or no damage. Earthquakes are fairly common in parts of Siberia, for example, but seldom make the news because the hardly anybody lives there.

The Haiti earthquake, however, struck a densely populated part of a densely populated country. Haiti’s population of 9.2 million people live in a country about the size of Maryland (making it the second most densely populated country in the Americas, after El Salvador.) The epicenter of the quake was just south of Port-au-Prince, the country’s  largest city and most densely populated area. Had the epicenter of the quake been a rural part of the country, the damage would have been considerably less severe.

Economic geography also plays a role in determining the extent of damage and loss of life in earthquakes. Wealthy countries like the United States, Japan and New Zealand are located near tectonic plate boundaries, and are also periodically struck by earthquakes. But these countries can afford  geologists to assess where quakes are most likely,  and engineers and architects to design earthquake resistant roads and buildings. When earthquakes occur, they have the expertise and resources to mount effective search and rescue campaigns, hospitals and medical personnel to treat the injured, and funds to rebuild in the quake’s aftermath.

In 1995, a shallow earthquake with a magnitude of 7.2 struck near Kobe, a Japanese city larger and more densely populated than Port-au-Prince. Many buildings were damaged, a highway collapsed, and 5,100 people lost their lives. This was a terrible disaster, to be sure, but even at this early stage it seems certain that far most people in Haiti will lose their lives or their homes. The reason: Japan is one of the wealthiest countries in the world, and Haiti is one of the poorest. And, as Nicholas Kristof observes in his blog “Frequently what kills people in … disasters isn’t just nature but its interconnection with poverty.”

Every year United Nations Development Program ranks the countries in the world on the basis of their Human Development Index, essentially a measure of human material wellbeing. In 2009, Haiti was came 149th out of 182 countries ranked by the UNDP. Its ranking was ahead of that of most of Sub-Saharan Africa, but far behind other Latin American and Caribbean countries. Average life expectancy in Haiti is 61 years, and four out of ten Haitians are illiterate. According to the World Bank, the country’s Gross National Income per capita was $560, and more than half the population lives on less than one dollar a day and 78% on less that two. Not everybody in Haiti is poor, though. One percent of the country’s population controls nearly half of Haiti’s wealth.

In this earthquake, it appears that  the worst hit areas of  Port-au-Prince are also its poorest areas, where tens of thousands of people live in densely packed shantytowns. Like shantytowns anywhere, Haiti’s shantytown are usually on the least desirable land. The Canapé Vert area of Port-au-Prince is such a place; steep hillslopes make the land useless for most purposes, so poor people have moved in and built their homes here. The photograph on the left shows Canapé Vert in 2004. Residents of shantytowns usually build their homes themselves, with whatever they can afford and whatever is available nearby: wood, mud, cheap concrete or bricks. This means that the homes are often not very sturdily constructed. In an earthquake-prone area like Haiti, this means that the poorest and most densely populated areas are often also the most vulnerable to damage. The photograph below shows part of Canapé Vert after the earthquake (it is impossible to tell, though, whether this is the same area pictured in the photograph above.)

But it is not only the poorer areas of Port-au-Prince where buldings are poorly constructed. According to American architects and engineers who have worked in Haiti, “most if not all of the buildings have major engineering flaws.” Because of large scale deforestation, wood is scarce and expensive, so most buildings are made of poured concrete or block. But concrete is imported and therefore expensive, so it is frequently diluted by adding sand to the mix. Steel reinforcing is also expensive, so builders often skimp on it too. It is hardly any wonder that so many buildings succumbed during the earthquake.

Political Geography. Haiti is not only the poorest country in the western hemisphere, it has historically also been one of the most unstable politically. The country managed to throw off French colonial control – and slavery – in the early 19th century, making it the first country in the Caribbean to attain its independence. But for much of its subsequent history, the country has been wracked by conflict between its small French-speaking minority and its poor, Creole speaking black majority (decendants of slaves brought to the country under French rule.)

During the late 20th century, the country was forced to endure near three decades of dictatorship under Francois “Papa Doc” Duvalier and his son, Jean-Claude, or “Baby Doc.” Their rule was brutal, and resulted in the deaths of tens of thousands of people. The election of a civilian leader, Jean-Bertrand Aristide, in 1990 gave many hope, but he was soon overthrown in a military coup. Backed by US military intervention, Aristide was restored to power in 1994, but in the following decade years of his rule, the situation in Haiti did not improve much. He was eventually ousted in 2004, and a UN stabilization force was sent to the country to help end widespread clashes between gangs and political groups. But widespread violence continued to plague the country, and the human rights situation remained bleak.

A Natural Disaster?

There is no such thing as a purely natural disaster. When the earth shakes, a volcano erupts, or a hurricane strikes, we measure its impact mainly by the toll it exacts on human beings and the infrastructure that sustains them. This impact is partly a consequence of the intensity of the natural event, but that impact is either exacerbated or mitigated by the various geographies of the disaster. How many people live there? Where, exactly, do they live – on hillslopes, in valleys, on flat land, or along the ocean? How wealthy are they? How well are there homes built? What building regulations exist in the area, and how well are they enforced? How extensive is the  transportation and communication infrastructure in the area? How well developed is the medical infrastructure of the area?

Yesterday’s earthquake was not only powerful, but it also struck just about the worst possible place at the worst possible time. It struck the most populated part of one of the world’s poorest countries less than a year after a series of damaging storms. It struck a place where a history of political instability and ineffectual government meant that infrastructure was meager, urban planning was poor non-existent, and building codes were weak or weakly enforced. Rescuing quake survivors will obviously be very difficult, as will treating their wounds and tending to the needs of survivors. Finally, reconstruction will require far more resources than Haiti has or is ever likely to have.

What it already clear is that Haiti will need all the help it can get in terms of material resources, human expertise, and political support. The devastation will be severe no matter what happens, but each one of us can help Haiti, albeit in small ways. For a start, we can share our resources with those in need (I have listed below some worthy organizations that are now accepting donations to help the residents of Haiti.) Second, we can make sure that we educate ourselves about this tragedy, and what makes ‘natural’ disasters so disastrous. That way we will be in position to foresee them, and help others do likewise. And third, we can make sure that we, and our political leaders, don’t forget Haiti after the camera crews and reporters leave.

Update: For a persuasive response to the pernicious argument that there is no point in sending assistance to Haiti, take a loook at this column by Nicholas Kristof.

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For more information, see…

Country profile: Haiti, from BBC News.

Information on the Haiti earthquake from the U.S. Geological Survey (USGS).

This Dynamic Earth: The Story of Plate Tectonics (USGS)

And also look at Google Earth’s images and information from Haiti.

To help. consider making a donation to…

Partners in Health “At its root, our mission is both medical and moral. It is based on solidarity, rather than charity alone.”

Medicins Sans Frontiers (Doctors Without Borders)

International Committee of the Red Cross (ICRC)

World Food Programme.

Save the Children.

Note: I am not an expert on Haiti, or on earthquakes. If anyone reading this post spots any errors or significant omissions, I encourage you to contact me or post a comment here.

Donald N Rallis

Tags: Haiti, Plate tectonics

This entry was posted on Wednesday, January 13th, 2010 at 4:21 pm and is filed under Haiti, Plate tectonics. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.