"Volcanic activity of the 2,329 meter high mountain is still high and tremors are fluctuating with an increasing tendency," he said at the post at the village of Ngadisari, Sukapura, Probolinggo.
On December 12 from 06.00 to 12.00 hours the tremor was recorded with a maximum amplitudo of between 3 and 22 millimeters but the dominant amplitudo was recorded at 5 millimeters.
"Visually the mountain could be seen clearly with clouds. The weather is fine with temperature at between 15 and 22 degrees Celsius and a soft breeze blowing," he said.
Sulfatara smoke from the crater of the mountain was seen grey to black with medium to maximum thickness and strong pressure billowing up between 200 meter and 400 meter towards southwest and east to west.
Visually medium intensity rain at a 4 millimeter rate of rainfall was also seen at the mountain but the danger status of the volcano still remained at an alert level.
"The spread of volcanic ash is determined by the direction and speed of the wind. In the past six hours it went westward and southwestward to Pasuruan and Malang regions," he said.
Based on the recommendation of PVMBG the area within a radius of 2.5 kilometers from the crater was closed for tourists as well as for activities of villagers, he said.
"I appeal to villagers and tourists to not conduct any activity within a radius of 2.5 kilometers from the crater for fear of thick Sulphur from the mountain that could cause respiratory problems and also sudden small explosions from the crater," he said.
Mount Bromo tourism activity has been closed since December 4 until further notice, head of the Bromo Tengger Semeru National Park Ayu Dewi Utari said.
"We keep coordinating with PVMBG with regard to the activity of Mount Bromo and due to the Alert III status we have closed the Bromo tourism area for any kind of activity," she said.