(Updates with aftershocks, more details)

LOS ANGELES, Aug 9 (Reuters) - A small earthquake hit the northern Los Angeles area just before 1 a.m. (4 a.m. EDT) on Thursday, waking residents across a broad swathe of the area, but there were no immediate reports of significant damage.

The 4.5 preliminary magnitude quake was centered 4.1 miles (6.6 km) north-northwest of the suburb of Chatsworth, according to the U.S. Geological Survey. It was extremely shallow, at only 3 miles (5 km) deep.

Chatworth, the unofficial capital of the porn movie industry, is about 32 miles (51.5 km) northwest of downtown Los Angeles.

Residents reported a strong jolt, followed by a lot of shaking. Some said pictures fell off walls, water sloshed around in toilets, and television sets wobbled on cabinets. A police spokesman said the quake triggered hundreds of alarms.

It was followed by two aftershocks, both with a preliminary 1.6 magnitude.

Chatsworth is just six miles (10 km) west of Northridge, the epicenter of the magnitude 6.7 quake that killed 57 people and injured more than 9,000 in 1994.

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