Some of the maps date back to the 1880s, offering detailed topographical glimpses of the region when foreign occupations and colonialization were common, said Shigeru Kobayashi, professor at Osaka University.

"We talk about the deforestation of Southeast Asia," he said, with old maps showing which areas have been affected. "The maps could also show how cities have changed between then and now. It's quite educational."

Kobayashi is part of a team, led by scholars from several Japanese universities, that is putting the maps on the Internet.

"We view this as a shared asset of significant educational value for all mankind," he said.

Until the end of World War II, the Japanese military created, copied and stole maps of the vast region stretching from Alaska to Australia, and from the Korean peninsula to Pakistan.

Certain regions, including China, the Korean peninsula, Sakhalin and Taiwan -- which Japan occupied or colonized until the end of the war -- were mapped more frequently than others.

The military nature of the maps, some of which were created in secret, required researchers to be sensitive today, Kobayashi said.

The project has drawn some criticism online from residents of countries that fell victim to Japanese military aggression in the past, he added.

"We are aware of the moral responsibility. Our intention is to enhance friendly international exchange," he said.

The growing online map collection can be viewed at a Japanese-language Internet archive hosted by Tohoku University at http://dbs.library.tohoku.ac.jp/gaihozu/.

(c) 2009 AFP