CANBERRA, Nov. 26 -- Over 7,000 square kilometers of the seafloor have been searched so far but no debris has been found relating to the missing Malaysian Airline MH370, Judith Zielke, chief coordinator of the Joint Agency Coordination Center (JACC) for the search of Malaysia Airline MH370, said on Wednesday.

She also promised to update families of those onboard with the latest search information on a regular basis.

Based on a drift model, the debris of MH370, might possibly be first washed ashore to the west coast of Sumatra 123 days after the crash, Search Operation Coordinator Peter Foley said at a press conference held in Australian Transport Safety Bureau (ATSB), the main coordinating agency, in Canberra.

The plane disappeared with 239 people on board during a March 8 flight from Kuala Lumpur to Beijing and its whereabouts remains a mystery.

Foley added that the Commonwealth Scientific and Industrial Research Organization, the chief science body in Australia, is asked to develop a refined drift model to identify the wider areas where debris could possibly be washed ashore so that more people can be informed of the possibility and pay due attention.

Currently, there are three vessels out at the sea about 2,300 kilometers off the coast of Perth for the search, with 35 personnel on board each of the vessel working around the clock in shifts.

Fugro Discovery is resupplying at Fremantle while Fugro Equator is undertaking bathymetric survey. Both vessels are contracted by the Australian government.

Fugro Equator's mobilization to conduct underwater search activities has been postponed due to delays in the supply of the new deep tow winch and cable. The ATSB has therefore utilized the vessel effectively by continuing the bathymetric survey work.

Fugro Equator arrived in the search area on Nov. 21 and has since surveyed over 4,000 square kilometers, bringing the total area surveyed to over 170,000 square kilometers.

The third vessel, GO Phoenix, contracted by the Malaysian government, continues to conduct underwater search operations in the assigned search area.

Zielke said the priority of the search operation at this stage is to complete the priority area of about 60,000 square kilometers before weather condition worsens in winter.

She said that JACC is trying its best to respond to queries from victim families through email, letters or tele-conference.