[News Today] Jitters rise over sinkholes

[LEAD]
Recovery efforts continue at Seoul's Gangdong-gu District where a sinkhole opened up in the middle of a road, claiming one life. Concerned, more and more people are demanding the release of related data, including risk maps.

[REPORT]
A sinkhole with a diameter of 20 meters suddenly opened up in the middle of a road.

Currently work is underway to fill up the space.

Traffic will resume from the night of April 20 but residents are still nervous.

Lee Sook-yeong / Nearby vendor
I imagine the road sinking every single day. It's nerve-racking. I can't sleep.

An underground construction that was cited as a possible reason for the collapse is still ongoing.

Local resident /
I heard a high speed rail to Pocheon will also be built further down. How can the ground stand the pressure.

There were 251 sinkhole incidents reported in Seoul last year up more than three fold from two years ago.

But with no information provided, locals have no idea what to look out for.

Gwon Il-soo / Local resident
I hope more attention is given to ways people can check sinkhole related information in advance.

It's been decided that ground penetrating radar tests will be held more frequently. But their limitations are quite obvious.

The equipment can only observe near the surface area which does not cover most excavation constructions that take place deeper underground.

Plus, there's only seven units of the equipment available in Seoul.

Prof. Choi Myeong-ki / Korea industrial site professors group
Early detection is key. A GPR probe can do it for shallow levels. For deeper sites, a monitoring can be used to assess changes to ground conditions.

The Seoul branch of the main opposition Democratic Party held a press conference, urging the disclosure of what's called a sinkhole safety map. Former ruling People Power Party chair Han Dong-hoon has also called on authorities to publicize areas at high risk of soil collapse.