A magnitude 6.7 earthquake struck Japan’s north-eastern region at 11:44 local time (02:44 GMT) on Friday. Here's what to know: We're closing our live coverage now, but you can read our earlier story about the megaquake that Japan is expecting. Thank you for joining us. After a magnitude 7.5 earthquake struck north-eastern Japan on Monday, authorities again warned of the possibility of a future megaquake. For a while now, Japan has been bracing for the "big one" - a once-in-a-century quake. These so-called "megathrust" earthquakes tend to strike every hundred years or so, often in pairs: the last ones were in 1944 and 1946. In September, Japan's earthquake investigation panel said there was a 60-90% chance that a megaquake would occur in the Nankai Trough - an area of seismic activity which stretches along Japan's Pacific coast - within the next 30 years. They had warned earlier that such an event could trigger a tsunami of more than 20m (66ft), causing around 300,000 deaths and trillions of dollars in economic damage. The tsunami advisory for areas along Japan's Pacific coast has been lifted, according to the Japan Meteorological Agency. The devastation caused by the 2011 earthquake and tsunami Earthquakes are a part of life in Japan, which experiences about 1,500 quakes a year. The country sits on the Ring of Fire, a Pacific region where many tectonic plates meet, resulting in volcanoes and frequent earthquakes. The vast majority do little damage, but there are some - like the one which struck in 2011 measuring magnitude 9.0, sending a tsunami into the north-east coast and killing more than 18,000 people. With each major quake Japan has learned important lessons about adaptation. It has adjusted its engineering and building codes to better protect residents from tremors. Waves up to 20cm have hit the shores of Aomori and Hokkaido prefectures so far, according to the JMA. Tsunami advisories have been issued in those areas. After the magnitude 7.5 earthquake earlier this week, several tremors have occurred in the same area. Officials, who told people to expect further quakes, have urged people in affected areas to stay vigilant and move to higher ground. Japanese prime minister Sanae Takaichi has just said that the quake does not fall under the megaquake advisory that authorities issued earlier this week. As we reported earlier, authorities had warned that a stronger tremor could occur after a magnitude 7.5 earthquake struck northeastern Japan on Monday. But Takaichi said today that people should remain vigilant check evacuation routes and their emergency supplies. There are "no immediate signs of abnormalities" at nuclear facilities around the region where the quake hit, Japan's Nuclear Regulation Authority has said. In 2011, a catastrophic earthquake - the most powerful ever recorded in Japan - hit Japan's Fukushima prefecture and sparked a major nuclear disaster after gigantic waves flooded reactors at the Fukushima Daiichi power plant. What the Japanese authorities have issued today is a tsunami advisory - warning of waves reaching one metre (3.3ft). Under this advisory, residents are told to stay away from water and coastal areas. This is the lowest level in the Japan Meteorological Agency's three-tier alert tsunami system. One level above an advisory is a tsunami warning, which is issued when authorities expect high waves (up to 3m) and damage to low-lying areas. In this case, people have to evacuate immediately to higher ground. The next on the scale is a major tsunami warning, issued for waves predicted to be more than 3m. Residents will also be ordered to evacuate immediately. Wooden structures are expected to be "completely destroyed and/or washed away", according to the JMA. Tsunami waves of 20cm (8in) have been recorded in Hachinohe city in Aomori Prefecture, according to the Japan Meterological Agency. The earthquake today comes just days after a magnitude 7.5 earthquake shook the same region. That quake, which also struck off the coast of Aomori, injured more than 50 people, authorities said. Authorities warned that a stronger tremor could occur, urging people to remain on high alert for at least a week. They also told people to check evacuation routes and prepare emergency kits. This also comes as Japan is anticipating a megaquake along its Pacific coast. Experts have warned of a 60-90% chance that such a quake could happen within the next 30 years. The red X marks the earthquake's epicentre After the initial magnitude 6.7 earthquake struck at 11:44 local time (02:44 GMT), there have been three aftershocks with magnitudes ranging from 4.5 to 5.7. Its epicentre is off the eastern coast of Aomori Prefecture, according to the Japan Meteorological Agency (JMA) The JMA has warned that we may see tsunami waves of up to one metre (3.3ft). Evacuation notices have been issued to some 6,000 people in Mutsu city, Aomori Prefecture, according to Japanese emergency warning app NERV. A magnitude 6.7 earthquake has struck Japan’s north-eastern region, according to the Japan Meterological Agency. It happened at 11:44 local time (02:44 GMT) at a depth of 20km (12.4mi), and was followed by several smaller quakes. The agency has issued a tsunami advisory for parts of Japan's eastern coast, warning that the waves could reach up to one metre (3.3ft). Today's earthquake comes after a magnitude 7.5 quake struck the same region earlier this week, injuring dozens of residents. We’ll bring you the latest as we get them - stick with us.