Sense of security on shaky ground; Bay State not immune to earthquake damage.Byline: Bill Fortier
Earthquakes have been big news recently.
A late-September temblor caused extensive damage to American Samoa American Samoa, officially Territory of American Samoa, unincorporated territory of the United States (2000 pop. 57,291), comprising the eastern half of the Samoa island chain in the South Pacific. and created a tsunami that caused water to rise about a foot as far away as the California coast, and two more earthquakes in the South Pacific were recorded earlier this week.
Most people know about earthquakes in California and Alaska where people use the 1964 Good Friday earthquake The Good Friday Earthquake (also called the Great Alaska Earthquake) of Friday, March 27, 1964 (Good Friday, a Christian holy day associated with a historical earthquake), 5:36 P.M. AST (03:36 3/27 UTC) had a magnitude of 9. that measured a magnitude 9.2 as a major marker in their lives.
So what about Central Massachusetts and New England New England, name applied to the region comprising six states of the NE United States—Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, and Connecticut. The region is thought to have been so named by Capt. - how vulnerable is this area to an earthquake?
Massachusetts may never experience an earthquake like the big one scientists have been predicting in California, but we could experience one big enough to cause billions of dollars of damage, according to according to
1. As stated or indicated by; on the authority of: according to historians.
2. In keeping with: according to instructions.
Massachusetts Emergency Management Agency The Massachusetts Emergency Management Agency (MEMA) is a commonwealth of Massachusetts agency. The Massachusetts Emergency Management Agency is the Agency that coordinates Federal, State, local and private resources throughout the Commonwealth during times of disasters and spokesman Peter Judge said New England averages about six minor tremors a year; for the most part, they cause only shelf rattling and dish shaking. People usually feel an earthquake when it exceeds a magnitude of 3.2. Damage ordinarily does not occur until a reading of 5.0 is reached.
Studies have shown that New England can expect an earthquake severe enough to cause major damage about once every 300 years, although 122 years between 1633 and 1755 seemed especially active.
A 1633 earthquake with an epicenter in Quebec City was strong enough to knock over chimneys in Boston. Another strong earthquake five years later caused major damage in Boston and inland.
A 1755 earthquake near Cape Ann Noun 1. Cape Ann - a Massachusetts peninsula to the north of Boston extending into the Atlantic Ocean
Bay State, Massachusetts, Old Colony, MA - a state in New England; one of the original 13 colonies , believed to have been between magnitude 6.5 and 7.0, caused much damage in Boston, according to John E. Ebel, director of the Weston Observatory, who has written extensively about this area's earthquake history.
The geology of the East Coast means the shock wave from earthquakes can travel over a much wider distance than in the West, which, according to Mr. Ebel, is why an 1886 earthquake in Charleston, S.C., estimated at 7.3, shook areas as far north as Boston.
Mr. Ebel and George C. Klimkiewicz, president of Weston Geophysical Engineers Inc. of Acton, said there is little doubt that more similarly strong earthquakes are in our future.
"It's happened in the past," said Mr. Klimkiewicz, whose company evaluates seismic hazards for large construction projects. "The processes that were ongoing in the past will continue to be ongoing in the future."
"In any given year, there is a low probability we'll be hit with a big earthquake," Mr. Ebel said. "But in my opinion, we could have an even larger one than the 1638 or 1755 earthquakes."
State officials were concerned enough about earthquakes that building codes that went into effect in 1975 called for provisions that would at least lower the amount of damage from a quake, said Edward S. Fratto, executive director of the Northeast States Emergency Consortium.
Among the chief authors of the building code in 1975, and revisions since then, is Norton S. Remmer, a Worcester resident and former Worcester building commissioner.
Mr. Remmer, who was commissioner from 1976 to 1986, is a code consultant. He said major earthquakes in Peru Earthquakes in Peru are common occurrences as the country is located in a seismic zone. The interface between the Nazca and South American tectonic plates is located near the Peruvian coast. These plates are converging at a rate of mm ( in) per year. and China in the 1960s which killed thousands of people were the impetus for upgrading safety measures safety measures,
n.pl actions (e.g., use of glasses, face masks) taken to protect patients and office personnel from such known hazards as particles and aerosols from high-speed rotary instruments, mercury vapor, radiation exposure, anesthetic and for large buildings erected in the state. For example, he said new construction since 1975 calls for steel reinforcements in walls of new, large buildings.
Earthquakes in California and New England are caused by two different geological processes, experts say.
California is along the edge of two major tectonic plates This is a list of tectonic plates on Earth. Tectonic plates are pieces of the Earth's crust and uppermost mantle, together referred to as the lithosphere. The plates are around 100 km (60 miles) thick and consist of two principal types of material: oceanic crust (also called , Mr. Ebel explained. While Los Angeles Los Angeles (lôs ăn`jələs, lŏs, ăn`jəlēz'), city (1990 pop. 3,485,398), seat of Los Angeles co., S Calif.; inc. 1850. is on the eastern edge of the Pacific plate, San Francisco San Francisco (săn frănsĭs`kō), city (1990 pop. 723,959), coextensive with San Francisco co., W Calif., on the tip of a peninsula between the Pacific Ocean and San Francisco Bay, which are connected by the strait known as the Golden , which is 400 miles to the north, is on the western edge of the North Atlantic plate. People flying into San Francisco or Los Angeles can look out a window and see evidence of previous earthquakes. In some places it is like looking at a shaken-up puzzle, Mr. Ebel said. Earthquakes there happen when the two plates collide or rub together under the earth's surface Noun 1. Earth's surface - the outermost level of the land or sea; "earthquakes originate far below the surface"; "three quarters of the Earth's surface is covered by water"
surface , he said.
New England is on the same North American plate The North American Plate is a tectonic plate covering most of North America, extending eastward to the Mid-Atlantic Ridge and westward to the Cherskiy Range in East Siberia. as San Francisco, Mr. Ebel said, adding that another large tectonic plate is under the middle of the Atlantic Ocean. Our quakes are caused by underground movement within the North American plate. Mr. Ebel used the analogy of squeezing a brick with a vice to the point at which it cracks in a certain area as the main reason quakes occur in this part of the country.
Despite changes in building codes, experts are worried about the damage that could occur if an earthquake, similar in severity to the one in 1755, struck.
Mr. Ebel said damage can be especially severe if an earthquake hits an area built on fill.
"The damage to Boston could be several billion dollars because about two-thirds of the downtown is built on fill," he said.
Mr. Remmer added, however, that while there could be major damage, the city would recover.
"There wouldn't be many total collapses, if any," he said.
Mr. Ebel said the 1755 earthquake caused some damage as far inland as Springfield. When told that one of this area's shopping centers - the Auburn Mall - was built on fill, he said it wouldn't collapse, "but there certainly would be some shaking."
ART: PHOTOS; GRAPH; MAP
CUTLINE: (1) Norton S. Remmer (2) John E. Ebel, director of the Weston Observatory, who has written extensively about New England's earthquake history. (GRAPH) Richter scale (MAP) Earthquakes in Massachusetts
A person who takes photographs, especially as a profession; a photographer. : (2) THE BOSTON GLOBE (GRAPH), MAP) T&G Staff/DON LANDGREN JR.