LOPPERSUM, the Netherlands -- Jannes Kadyk's modest brick home suffered more than $5,000 in damage. Bert de Jong's more stately home will need about $500,000 to get back into shape.
Both houses, like thousands of others, were damaged during recent earthquakes that have shaken the flat farmland in this area dotted with villages and tucked up against the North Sea.
The quakes were caused by the extraction of natural gas from the soil deep below. The gas was discovered in the 1950s, and extraction began in the 1960s, but only in recent years have the quakes become more frequent, about 18 in the first six weeks of this year, compared with as few as 20 each year before 2011.
Chiel Seinen, a spokesman for the gas consortium known as NAM, said the extraction had created at least 1,800 faults in the region's subsoil.
"These faults are seen as a mechanism to induce earthquakes," he said.
The findings in the Netherlands parallel the anxiety about hydraulic fracturing technology in the United States, where several states have halted drilling temporarily, though more commonly out of fear that chemicals used in the process may pollute water sources.
This month, the New York State Assembly voted to block so-called fracking, the process in which water is blasted through rock at high pressure to extract gas, until 2015, requiring further study on its environmental impact.
This is not Haiti. The worst tremor, last August, had a magnitude of 3.4, hardly enough to cause widespread devastation. Yet the number of claims for damaged property is already in the thousands, and the company extracting the gas, a consortium of Shell and Exxon Mobil, has set aside $130 million for measures to strengthen buildings against the shocks. Yet most troubling is that experts at government agencies are predicting that the quakes will worsen, to between a magnitude of 4 and 5.
Is the big one yet to come? Mr. Kadyk, 62, a retired city employee, pointed to cracks around doors and windows in his two-story brick home. He said he was "not an expert, so I cannot say yes or no, but the real experts say if we don't stop extracting gas, the country risks further earthquakes."
Yvonne Doesburg, who runs a small restaurant and hotel called De Oude Smidse near Mr. Kadyk's home, recalled the August quake, which had its epicenter in Loppersum. "The house shook enormously; it was scary," she said. Asked whether people expected worse, she replied, "The fear is there."
Ms. Doesburg's husband, Jorg Zart, believes the drilling should go on nonetheless. "It brings jobs," he said, "and traditionally, this was one of the poorest regions of Holland."
His wife dissents. "The money is made here, but spent elsewhere," she said.
Public sentiment sides with Ms. Doesburg. Membership in a grass-roots organization called the Groningen Soil Movement, for the province of Groningen, where Loppersum lies, has jumped to 800 people from 200 in the past two years. In a survey of 686 residents published this month, almost two-thirds said they wanted the amount of gas extracted to be cut; 16 percent wanted it stopped altogether.
"We believe safety is not the top priority," said Daniella Blanken, a computer programmer and a Soil Movement board member.
The national government in The Hague insists it is. The northern region is particularly vulnerable because much of it lies below sea level, protected from North Sea waters by huge dikes. If earthquakes threatened the dikes or the intricate system of canals and locks that lace the land, the loss of life could be catastrophic.
Albert Rodenboog, 60, the mayor of Loppersum for the past decade, compares the government to an acrobat doing a split: While The Hague has safety in mind, he explains, it is also bound by contractual obligations and serious financial considerations.
"We have to reckon in the future with heavier quakes, with heavier damage," the mayor said. "But there are domestic delivery contracts, export contracts."
The region supplies natural gas to Germany, Belgium and France, and government profits on the sale of gas amount to more than $15 billion annually, Mr. Rodenboog said, money the government can hardly do without at a time of weak economic growth and reduced revenues.
In January, Henk Kamp, the minister for economic affairs, laid out the options to Parliament in a four-page report. Studies by Shell and Exxon Mobil, as well as by government agencies like the state mining regulator, showed that prior assumptions about the size of possible earthquakes were wrong. "Tremors greater than 3.9 are possible," he wrote. The mining agency in particular, he said, advised him to urge Exxon Mobil and Shell to "reduce gas extraction in the Groningen field as quickly and as much as is feasibly possible."
Yet the minister said he would not make a final decision before the end of this year.
Developments in the region are watched closely even beyond the Dutch borders because of the debate in Europe about the safety of fracking.
But Mr. Seinen, the gas consortium spokesman, said fracking was not used in the Netherlands because of the excellent porosity of the rock under Groningen Province. "It is the most conventional gas-winning process," he wrote in an e-mail. "Drill a hole and the gas flows automatically."
Mayor Rodenboog says he recognizes people's fears. "There is more than the material loss," he said. "People are mentally stressed by anxiousness about what is coming in the next years." Yet he said he trusted the government to take the time before making a decision.
Mr. de Jong, 60, a civil engineer by training who now heads the local school board, disagreed. The risk of greater tremors, he said, "affects the whole region. Banks don't want to invest anymore, and you cannot sell a house here."
Ms. Blanken of the Soil Movement described profits for the region from the sale of gas as minuscule. "About one-half of 1 percent of the gas income flows back," she said.
Mr. de Jong's farmhouse was built in 1894, when farming brought considerable wealth to the area. Elegant Art Nouveau ceilings with carved-wood flowers were installed before 1920, he said. Yet after quakes last August and in February, the ceilings are cracked, and the one in the dining room threatens to fall. The brick walls of the house now bulge by about four inches and will require buttressing, as will two brick chimneys that are in danger of collapse. A balcony that runs along the facade, supported by slender cast-iron columns, must be replaced.
"We are not sure what these lighter tremors are doing," he said, sipping tea in his living room. "Maybe they are destroying the buildings piece by piece."
"Yet if people are killed in the area, what then?" he asked.
"We feel taken hostage," he said. "A hostage in your own home."world
This article originally appeared in The New York Times.