MANILA (PNA) -- The Philippine Institute of Volcanology and Seismology (Phivolcs) on Thursday instructed certain provinces in the country to monitor the change in sea levels of their respective coasts following the magnitude 7.9 earthquake which jolted Chile.In its Tsunami Information No.1 released Thursday morning, Phivolcs, in particular, issued the advisory to the provinces of Batanes Group of Islands, Sorsogon, Cagayan Northern Samar, Ilocos Norte, Eastern Samar, Isabela, Leyte,Quezon, Southern Leyte, Aurora, Surigao del Norte, Camarines Norte, Surigao del Sur, Camarines Sur, Davao Or