CHINA — Obtaining crucial financial information, or even sending a simple email, was no easy task in Asia on Wednesday after telecom cables were damaged by earthquakes that hit Taiwan this week, exposing the frailties of the lines, laid deep underwater, that have formed the arteries of the region’s economic growth in recent years.

From South Korea to South Australia, universities, banks and stockbrokers were complaining of major connectivity problems more than 48 hours after the quakes.

Telephone traffic was slowly getting back to normal in some partsof Asia, but many operators in the north of the continent were struggling to get up to full speed after one of the worst tech disruptions to hit the area.

Most Internet access in China was still down following the quakes. State telecom operator CNC said it was working to fix the problem, but there were fears it could take three weeks before a return to normal functioning.

Undersea fiber-optic cables carry more than 95% of all international telecommunications thanks to their strength, capacity and connection quality, but they have long been seen as a potential weak link in the information superhighway.

Laid on the ocean floor, the cables are prone to damage from driftnet fishing; anchors; attacks by sharks lured by the electromagnetic pulse given off by the wiring; and, in some areas, seismic activity. There is little alternative, however, other than satellite technology, which can be expensive and does not allow the same capacity or quality of transmission.

Plans to lay cables on less earthquake-sensitive paths were stymied by the bursting of the tech investment bubble in 2001.