Rare and High Impact Events
Accumulated by Charles Kim Electrical and Computer Engineering, Howard University, Washington, DC.

25 MARCH 2012: [Huffington Post] WASHINGTON -- A mild 3.1 magnitude earthquake rocked much of Central Virginia late Sunday night near the epicenter of the August 2011 5.8 magnitude temblor that was felt across much of the East Coast. According to a U.S. Geological Survey's Did You Feel It? map, people who reported feeling the quake were primarily in an area roughly bounded by Charlotttesville, Richmond and Fredericksburg. The quake, which hit at 11:21 p.m., had an epicenter about 8 miles from Mineral, Va., and 88 miles southwest of the nation's capital. There was no reported damage, according to WTOP. Roughly 100 aftershocks have been recorded in the Central Virginia Seismic Zone since last year's 5.8 magnitude earthquake.

25 MARCH 2012: [AP] SANTIAGO, Chile—A magnitude-7.1 earthquake struck central Chile Sunday night, the strongest and longest that many people said they had felt since a huge quake devastated the area two years ago. There were no immediate reports of deaths or major damage. The quake struck at 7:30 p.m. about 16 miles north-northwest of Talca, a city of more than 200,000 people where residents said the shaking lasted about a minute.

20 MARCH 2012: [CBS] A strong 7.4-magnitude earthquake hit Mexico on Tuesday, shaking central and southern parts of the country and swaying buildings in Mexico City. Plaster fell from ceilings and windows broke in the center of the capital, but the president said there were no immediate reports of major damage.The initial quake in Guerrero state was followed by a less powerful, magnitude-5.1 aftershock that also was felt in the capital. Frightened workers and residents poured into the streets of the capital just minutes after noon local time (18:02 GMT). Telephone service was down in the city and throughout the area where the quake was felt. About 40 passengers were stranded for a short time on the Mexico City airport air train, but later released. The airport closed for a time but officials said there was no runway damage and they resumed operations. A pedestrian bridge collapsed and crushed a microbus in Mexico City, but there were still no reports of deaths. A building in the neighborhood of Condesa appeared to be on the verge of collapsing.

08 SEPTEMBER 2011: [CNN] A short-circuit at a substation in North Gila, Arizona, set off a series of failures that led to the massive power outage that left millions of people in California, Arizona and Mexico in the dark, San Diego Gas and Electric Co. President Michael Niggli said Friday. Niggli said automatic safeguards prevented the Thursday afternoon blackout from spreading even farther, but he said an investigation will be necessary to determine why safeguards that could have further limited the outage did not work. The San Onofre Nuclear Generating Station near San Clemente, California, which provides electricity for San Diego, remained offline Friday after automatically shutting down when the blackout cascaded across the power grid. The reactors at the San Onofre plant went into normal shutdown mode after the units detected "grid disturbance," said Eliot Brenner, director of the U.S. Nuclear Regulatory Commission's Office of Public Affairs. The shutdown posed no threat to workers or residents, he said. Fire officials praised people stuck in elevators for staying cool while waiting for rescuers to arrive, and police noted a lack of looting and other criminal activity. Officials also thanked the U.S. Navy for powering up generators aboard its many ships in port, freeing up the utility to restore power sooner to other customers. "I think it's one of these things that show people how important community is," San Diego Mayor Jerry Sanders said. [obrag.org] All of San Diego County as well as some parts of Orange County, Arizona and Mexico experienced a blackout for about 12 hours Thursday, September 8, 2011, one of the hottest days of the year although the blackout had nothing to do with air conditioning overload or any other kind of overload to the system. It was all caused by some electric company employee in Yuma, Arizona tripping the wrong switch accidentally or replacing defective monitoring equipment depending on which story you want to believe. Just think what could happen if someone such as a terrorist deliberately and determinedly wanted to cause harm to the six million people who were affected by the blackout! This blackout should be considered a dry run to what might happen if there were a major emergency, an actual cutting of the 500,000 volt transmission line between Yuma and San Diego. How easy would it be for someone to merely bomb one of the transmission towers in some remote area and bring the whole system down not to be recovered so easily as merely turning the power back on which is all San Diego Gas and Electric had to end up doing. Even that took them 12 hours! This power outage should be considered a dry run for such a terror attack or other major emergency, and, obviously, the system failed catastrophically for little reason. The entire electrical grid is in dire need of being overhauled and redesigned so that this type of failure caused by one person doesn’t happen again. There is no reason for a local power outage to be transmitted over the entire system. That’s totally ridiculous and unnecessary. There should be enough failsafe built into the system such that local failures are confined to local areas. This is a huge failure of centralized power generation and transmission. Instead the power grid needs to be redesigned as a distributed system. Power generated locally including solar or wind power should be able to power local needs without the possibility of being shut down by a systemic event. Distributed power generation rather than centralized power generation is the key.

23 AUGUST 2011: [USGS] The Virginia earthquake of 2011 August 23 occurred as reverse faulting on a north or northeast-striking plane within a previously recognized seismic zone, the Central Virginia Seismic Zone. The Central Virginia Seismic Zone has produced small and moderate earthquakes since at least the 18th century. The previous largest historical shock from the Central Virginia Seismic Zone occurred in 1875. The 1875 shock occurred before the invention of effective seismographs, but the felt area of the shock suggests that it had a magnitude of about 4.8. The 1875 earthquake shook bricks from chimneys, broke plaster and windows, and overturned furniture at several locations. A magnitude 4.5 earthquake on 2003, December 9, also produced minor damage. Previous seismicity in the Central Virginia Seismic Zone has not been causally associated with mapped geologic faults. Previous, smaller, instrumentally recorded earthquakes from the Central Virginia Seismic Zone have had shallow focal depths (average depth about 8 km). They have had diverse focal mechanisms and have occurred over an area with length and width of about 120 km, rather than being aligned in a pattern that might suggest that they occurred on a single causative fault. Individual earthquakes within the Central Virginia Seismic Zone occur as the result of slip on faults that are much smaller than the overall dimensions of the zone. The dimensions of the individual fault that produced the 2011 August 23 earthquake will not be known until longer-term studies are done, but other earthquakes of similar magnitude typically involve slippage along fault segments that are 5 15 km long. Earthquakes in the central and eastern U.S., although less frequent than in the western U.S., are typically felt over a much broader region. East of the Rockies, an earthquake can be felt over an area as much as ten times larger than a similar magnitude earthquake on the west coast. A magnitude 4.0 eastern U.S. earthquake typically can be felt at many places as far as 100 km (60 mi) from where it occurred, and it infrequently causes damage near its source. A magnitude 5.5 eastern U.S. earthquake usually can be felt as far as 500 km (300 mi) from where it occurred, and sometimes causes damage as far away as 40 km (25 mi). [CBS] MINERAL, Va. - The most powerful earthquake to strike the East Coast in 67 years shook buildings and rattled nerves from South Carolina to Maine on Tuesday. Frightened office workers spilled into the streets in New York, and parts of the White House, Capitol and Pentagon were evacuated. There were no immediate reports of deaths or serious injuries.The National Cathedral said its central tower and three of its four corner spires were damaged, but the White House said advisers had told President Barack Obama there were no reports of major damage to the nation's infrastructure, including airports and nuclear facilities. The National Parks Service says an inspection has revealed some cracking in the stones at the top of the Washington Monument. The NPS will have structural engineers evaluate the cracks on Wednesday to determine the best way to repair the Monument before it is reopened. The Washington Monument grounds have been reopened except for an area about 100 feet outside of the plaza. The U.S. Geological Survey said the quake registered magnitude 5.8 and was centered 40 miles northwest of Richmond, Va. Two nuclear reactors at the North Anna Power Station, in the same county as the epicenter, were automatically taken off line by safety systems, said Roger Hannah, a spokesman for the U.S. Nuclear Regulatory Commission. The earthquake came less than three weeks before the 10th anniversary of the Sept. 11 attacks, and in both Washington and New York it immediately triggered fears of something more sinister than a natural disaster. At the Pentagon, a low rumbling built until the building itself was shaking, and people ran into the corridors of the complex. The shaking continued there, to shouts of "Evacuate! Evacuate!" The Capitol reopened for members and staff, but not for the public. The Park Service closed all monuments and memorials on the National Mall, and ceiling tiles fell at Reagan National Airport outside Washington. All flights there were put on hold. "The Washington/Virginia, Philadelphia/Atlantic City/Pennsylvania, and New York area airports, except LaGuardia, all suspended flights briefly so airport operators could assess runway integrity," said FAA spokesperson Kathleen Bergen. "Operations resumed as soon as the airports determined that the runways and associated equipment and facilities were not damaged. LaGuardia never stopped flights. Dulles never stopped arrivals and only briefly stopped departures." In lower Manhattan, the 26-story federal courthouse in lower Manhattan, blocks from ground zero of the Sept. 11 attacks, began swaying, and hundreds of people streamed out of the building.

09 APRIL 2011:[AP] Four generators that power emergency systems at nuclear plants have failed when needed since April, an unusual cluster that has attracted the attention of federal inspectors and could prompt the industry to re-examine its maintenance plans. Three diesel generators failed after tornadoes ripped across Alabama and knocked out electric lines serving the Tennessee Valley Authority's Browns Ferry nuclear plant in April. Two failed because of mechanical problems and one was unavailable because of planned maintenance. Another generator failed at the North Anna plant in Virginia following an August earthquake. Generators have not worked when needed in at least a dozen other instances since 1997 because of mechanical failures or because they were offline for maintenance, according to an Associated Press review of reports compiled by the U.S. Nuclear Regulatory Commission. In the U.S., an average of roughly one diesel generator has failed when needed each year since 1997. Government researchers who examined diesel generator failures in the U.S. from 1997 to 2003 calculated the average odds that a diesel generator would fail to work at some point during an eight-hour run were slightly greater than 2 or 3 percent, depending on which database was analyzed. Even at low odds, a generator failure can turn serious when combined with other problems, notably human error.