Meanwhile, residents in many provinces were reminded by a warning of flashfloods and mudslides following heavy rains forecast throughout this week, in addition to other areas already affected.
The tremors felt in five districts in Chiang Rai were regarded as aftershocks of the March 25 earthquake, which measured 6.7 on the Richer scale, said Lertsin Raksasakulwong, a senior official in charge of earthquake detection and warning.
The first 3.9magnitude tremor was reported at 4.16am, the second 3.2 tremor at 4.24am, the third 4.6 tremor at 8.25am, and the last 4.0 tremor at 3.11pm. No details on epicentres or affected areas in Burma were forthcoming.
There was a 3.4 quake on Sunday, with its epicentre 24 kilometres away from Mai Sai district and 10km, underground, before the four quakes yesterday.
“The one quake last Sunday, and the four yesterday, have prompted a new way of analysing them all, because aftershocks after a major quake should have ended completely, and especially the quakes now occurring closer to Thailand,” he said.
Quakes in Burma could trigger a movement along the Mae Chan faultline in Thailand, which could inflict severe damage if it exceeded 4.5 in magnitude and 10km in depth.
The department’s statement also warned of mudslides in the northern provinces of Phayao, Lamphun and Lampang where there had been torrential rain and whose geographical structures and mountainous surroundings had contributed to greater risk of mudslides or landslides than others in the North.
In Lamphun, many homes along the Lee River were partially submerged and most farmland was inundated. In total, 740 homes in Lampang’s Serm Ngarm district located near the Mae Tam reservoir were flooded, with 2,000 occupants affected and partly evacuated.
In the South’s Ranong, a mudslide closed a lane of a major road while storms felled many trees, which briefly blocked another major road linking this province with Chumphon. Local authorities are advising residents of 84 villages in four Ranong districts to stay alert for floods