A shallow but powerful earthquake off the western coast of Sumatra in Indonesia triggered tsunami warnings in that country, as well as watches for western Australia on Wednesday evening, local time.

Australia’s Bureau of Meteorology issued a marine warning for distant Cocos and Christmas islands, according to mashable.com and other sources. It did not advise evacuations, but said strong and dangerous currents were possible, and residents should secure boats and avoid waterfront areas. The warning noted that a tsunami had not been confirmed.

The earthquake registered a 7.8 on the Richter Scale, according to the U.S. Geological Service (USGS), and it was centered only 10 kilometers under the ocean surface.

The Pacific Tsunami Warning Center in Hawaii said there is little danger of a tsunami directed at the Hawaiian islands from this particular earthquake.

Since that 2004 earthquake and resulting tsunami that killed 230,000 people in a dozen countries, scientists have worked to improve the detection and warning network for tsunamis, particularly in the Indian Ocean, deploying special buoys for this purpose.

Indonesia sits along the so-called “Ring of Fire” that forms an outline around the Pacific Ocean. Here the Earth’s plates are constantly grinding against one another, leading to the building of mountain ranges and volcanoes – and also the triggering of earthquakes.

According to the USGS, about 90 percent of the world’s earthquakes occur along the Ring of Fire.