September 21, 2017

Two days ago, on September 19, a powerful 7.1-magnitude earthquake struck central Mexico, collapsing buildings and killing more than 240 people in Mexico City, the capital, and in the states of Guerrero, México, Morelos, Oaxaca, and Puebla. The earthquake struck on the anniversary of a catastrophic 1985 earthquake that killed some 10,000 people in central Mexico. The quake followed another deadly temblor that hit southern Mexico earlier in September 2017.

Rescue workers call for quiet as they search a collapsed building in the Mexico City neighborhood of La Condesa following a powerful 7.1-magnitude earthquake on Sept. 19, 2017. The earthquake toppled buildings and killed more than 240 people in the region. Credit: © Alejandro Cegarra, Bloomberg/Getty Images

The earthquake’s epicenter was near the small Puebla city of Atencingo, about 75 miles (120 kilometers) southeast of Mexico City. The prolonged tremor hit at 1:14 p.m. local time—just two hours after an annual earthquake drill in Mexico City—shaking buildings and frightening people into the streets. Structures collapsed in several cities, obscuring the panicked survivors in dust clouds amid the blaring din of alarm sirens.

Emergency responders rushed to the first scenes of destruction. Unstable rubble and electric power outages hampered rescue efforts, and widespread damage meant many ravaged places went hours without help. Military personnel and civilian volunteers aided emergency workers as they searched through the night for survivors. Sniffer dogs followed human scents, and workers pleaded for silence, hoping to hear the calls of people trapped beneath the destruction. Many people were saved, but the body count rose quickly as splintered wood, shattered masonry, and chunks of concrete were frantically removed. Many people remain missing amid the devastation, and the disaster’s death toll—245 as of this morning—will almost certainly rise.

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On Sept. 19, 2017, a powerful earthquake hit central Mexico, killing more than 240 people in the Federal District of Mexico City and in the states of Guerrero, México, Morelos, Oaxaca, and Puebla. Credit: WORLD BOOK map

In Mexico City, more than 90 people have died, including 21 children and 5 adults killed when an elementary school collapsed in the city’s southern Coapa district. More than 70 people were killed in Morelos, just south of Mexico City, and more than 40 died in the epicenter state of Puebla. On the slopes of Popocatépetl volcano southeast of Mexico City, a church collapsed in the village of Atzitzihuacán, killing 15 people. Throughout the region, scores of buildings fell, ruptured gas lines sparked fires, and falling debris crushed cars on the streets.

Like the earthquake earlier in September in southern Mexico, Tuesday’s temblor struck near the Middle America Trench, a zone in the eastern Pacific Ocean where one slab of Earth’s crust, the Cocos Plate, is sliding beneath the North American Plate—a geological process called subduction. The Middle America Trench is part of the so-called Ring of Fire, an area of high seismic and volcanic activity that encircles the Pacific Ocean. The United States Geological Survey (USGS) issued an orange alert (the second-highest threat level) after Tuesday afternoon’s quake, warning of significant casualties and extensive and widespread damage. The alert was part of the USGS PAGER (Prompt Assessment of Global Earthquakes for Response) system that informs emergency responders, the media, and government and aid agencies of the scope of a potential disaster.

On Sept. 19, 1985, an 8.0-magnitude temblor killed some 10,000 people in Mexico City and nearby areas. About 400 buildings in the capital were destroyed in that disaster, and thousands of others suffered damage. Since then, Mexico has enacted tougher building codes and safety standards—moves that no doubt saved many lives 32 years later.

March 9, 2016

Next month, in April, a deep-ocean drilling project will begin off the Yucatán coast in the Gulf of Mexico. Most such oceanic drill projects are concerned with oil exploration. This isn’t your usual drill team, however. The drillers in this case come from the International Ocean Discovery Program, the National University of Mexico, and the University of Texas. And they will be drilling into Chicxulub Crater, an impact crater formed by a giant asteroid that helped kill the dinosaurs some 65 million years ago. They won’t be looking for oil; they’ll be looking for answers.

The Chicxulub Crater along the northern coast of Mexico’s Yucatán Peninsula formed when an asteroid hit the earth about 65 million years ago. Debris from the impact may have led to the extinction of the dinosaurs.
Credit: WORLD BOOK map

At the end of the Cretaceous Period, dinosaurs were the dominant land animals on the planet. Other reptiles filled the seas, and birds—descendants of dinosaurs—roamed the skies. Mammals existed, but they were far smaller and less common than today. Then, an asteroid at least 6 miles (10 kilometers) wide slammed into the Yucatán Peninsula, in present-day Mexico. The impact threw up large amounts of gas and dust into the atmosphere. This material would have blotted out the sun for many years. Plants that use sunlight to make their food would have died out, followed by the animals that ate them. With no more prey animals, large carnivores starved as well.

When the dust settled, about half of all species on Earth had gone extinct. All the dinosaurs—except birds—were dead. Only a few kinds of other reptiles survived. Mammals survived too and over time evolved to become the dominant large-bodied animals on land and in the sea.

The Yucatán asteroid formed a large impact crater, which is now partly on the peninsula and partly in the Gulf of Mexico. Tens of millions of years of plate tectonics and erosion have taken their toll on the crater, and it is barely visible in satellite images today. But the mark that it left in the rocks should still be clear.

The team plans to use a drilling ship to sample rock deep beneath the ocean floor. In drilling into the crater, scientists hope the presence (or lack) of microfossils (tiny preserved remains of ancient organisms) will teach them more about the nature of the asteroid impact and how quickly life returned to the area afterwards.

The drilling evidence may also better explain how responsible the impact was for the mass extinction at the end of the Cretaceous Period. Most scientists agree that the asteroid did most of the damage, but others argue that other causes, such as massive volcanic activity in present-day India, were more to blame. Such extinction hypotheses are not mutually exclusive, however: it may have taken more than one disaster to knock out the dinosaurs. In fact, they may even be linked. Recent studies have suggested that the Yucatán impact caused the spike in volcanism on the other side of the globe in India. Whatever the case, the drilling team will help get to the bottom of this and other stories, as well as to the bottom of the impact crater itself!

August 29, 2012

Hurricane Isaac barreled into the northern coast of the Gulf of Mexico on Tuesday, bringing storm surges, heavy rains, stiff winds, flooding, and threats of tornadoes. The Category 1 hurricane, which struck parts of Alabama, Louisiana, and Mississippi, was expected to reach New Orleans late this evening, seven years to the day that Hurricane Katrina slammed into the city. One of the most destructive storms in United States history, Katrina killed about 1,800 people and caused about $100 billion in damage. About 80 percent of New Orleans was flooded as parts of the city’s system of levees (flood barriers) failed. Most of the approximately 1,500 Louisianians who died because of the storm were from New Orleans.

Isaac made its first landfall at about 7:45 p.m. (EDT), about 95 miles (153 kilometers) south of New Orleans in Plaquemines Parish. The storm then wobbled westward and back into the gulf but returned for a second landfall at 3 a.m. (EDT) on Wednesday, near Port Fourchon, about 60 miles (97 kilometers) south of New Orleans. Heavy rainfall and storm surges along the Gulf Coast in Louisiana and Mississippi caused flooding as deep as 14 feet (4 meters) in some areas, sending residents who chose not to evacuate to the rooftops of their houses. Local residents and members of the National Guard mounted rescue operations in Plaquemines Parish, where a 12-foot (3.6-meter) storm surge overtopped (flowed over) an 18-mile (5.4-meter) section of levee.

By midday Tuesday, the slow-moving storm had essentially stalled, leading forecasters to predict that heavy rains would pound the area for several days. New Orleans could receive up to 20 inches (51 centimeters), said an official with the National Weather Service. Residents and officials in New Orleans were keeping a close eye on the city’s levees and pumps, which had undergone a $14-billion federal upgrade after the flood protection system had failed catastrophically during the much-stronger Hurricane Katrina.

A street intersection lies flooded near downtown New Orleans after Hurricane Katrina struck the city in August 2005. The hurricane caused many deaths and widespread damage. A combination of storm surge (a rapid rise in water levels produced when winds drive ocean waters ashore), heavy rainfall, and broken levees (walls to prevent flooding) caused water to cover most of the city. (© Chris Graythen, Getty Images)

Ahead of Isaac’s arrival, the governors of Alabama, Louisiana, and Mississippi ordered mandatory evacuations in some counties. The next day, U.S. President Barack Obama declared a state of emergency in Louisiana. troops were placed on stand-by alert to help communities affected by the storm. New Orleans officials also declared a state of emergency and provided buses for people to wished to leave their homes voluntarily.

Before hitting the Gulf Coast, Isaac–then a tropical storm–had lashed central and southern Florida with heavy rains and strong winds. The storm also caused the deaths of 24 people in Haiti and widespread damage along that country’s southern coast. The storm left 5 people dead in neighboring Dominican Republic.

Additional World Book articles:

• Corps of Engineers
• Federal Emergency Management Agency
• The Second Battle of New Orleans (a Special Report)
• City (2005) (a Back in Time article)
• Safety (2005) (a Back in Time article)