Seoul steps up sinkhole prevention efforts after fatal accidents
On March 24, a 20-metre-wide and 18-metre-deep sinkhole formed in Gangdong-gu, eastern Seoul. -- PHOTO: REUTERS
SEOUL (The Korea Herald/ANN): The Seoul Metropolitan Government announced on April 27 that it will introduce a ground subsidence monitoring network to prevent further sinkhole accidents.
Safety accidents involving sinkholes have drawn attention recently, after a 20-meter-wide and 18-meter-deep sinkhole formed in Gangdong-gu, eastern Seoul, on March 24, swallowing a motorcyclist who was declared dead the day after.
As numerous sinkhole sightings have been reported since, public concern over the phenomenon has grown significantly, with up to 50 locations in the capital city alone identified as at risk of sinkhole formation.
The new ground subsidence monitoring network, according to the city government, involves installing a bat-shaped column sensor 20 m underground. The sensor's antenna detects changes in geological layers within a 50 m radius and transmits the information to the central monitoring station. If anomalies are identified, appropriate measures will be taken by the authorities.
This is also an upgrade from the Ground Penetrating Radar system previously used by the city government, which emits high-frequency electromagnetic waves from the surface into the ground to detect sinkholes based on the reflected signals. Though the GPR system has been used nationwide, it is effective only up to around 2 m underground.
By May, the Seoul Metropolitan Government stated that it would install the new monitoring network at a construction site located near the site of the large sinkhole that formed in late March.
At the time of that accident, construction work was underway near the site to extend Seoul Subway Line No. 9, which the city government suspended, noting that the project could not be ruled out as a possible cause of the sinkhole.
As most large sinkholes begin to form 10 meters underground, the new monitoring network is seen as a more effective way to prevent sinkhole accidents while overcoming the limitations of GPR surveys.
However, the new ground subsidence monitoring network is not a perfect solution. While GPR systems can be moved throughout Seoul on vehicles, the monitoring network can only take measurements in specific locations where sensors are installed.
Due to such limitations, the city government added that it will install the ground subsidence monitoring network system at large construction sites like the one in Gangdong-gu while expanding GPR surveys for other major excavation sites.
Separately from the city, the central government included 2.27 billion won (S$2.08 million) in its supplementary budget to support ground exploration efforts.
However, it is unclear whether such spending will be effective, as even with additional equipment purchases, the limited depth of exploration reduces the overall effectiveness of these measures. This is because most of the sinkholes discovered so far have formed near large construction sites, where machines dig deep underground.
The central government will use part of its budget to invest in GPR systems.
Aware of the technical limitations, the government considered introducing GPR systems that penetrate deeply underground - though the plan fell through earlier this year due to concerns that its performance had not yet been sufficiently verified. -- THE KOREA HERALD/ASIA NEWS NETWORK
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
The Star
2 days ago
- The Star
No pay, all courage
IN the summer of 2023, Dimitris Marinelis spent days on the frontline of Europe's biggest wildfire in northern Greece, protecting homes and setting up anti-fire zones as flames engulfed a forest. Like the others on his team, Marinelis has not been paid a cent for his work – he is among thousands of volunteer men and women firefighters who juggle day jobs with battling Greece's devastating summer blazes, sometimes dropping everything to go wherever they are needed. 'I'm a businessman,' 54-year-old Marinelis, who runs a construction company, said at the volunteer team's base in the leafy upscale Athens suburb of Ekali. 'Then when the phone rings, when you have a shift ... you stop thinking about yourself and you start thinking about others,' he said. As climate change makes Greece hotter, drier and more vulnerable to wildfires, the government has said it will deploy a record 18,000 firefighters this year, up from around 15,500 in 2022, plus around 10,000 volunteers. It has also earmarked some €2bil (RM9.65bil) to buy new aircraft and will use nearly twice as many thermal camera drones that seek out fires as last year, one of which will be used by the Ekali team. 'Unfortunately, we're waiting for the worst and hoping for the best,' Marinelis said. Greece's fire service is a mixed model of permanent staff and seasonal workers, and has long been backed by volunteers, viewed by many Greeks as the heart of the country's firefighting efforts. Images of exhausted firefighters in blackened uniforms sleeping on the roadside are frequently posted online alongside messages of support. It is not always easy to keep the organisations going. Ekali team leader George Dertilis said his 60-member team depends on donations for equipment and trucks – one of which dates back to 1986. Some of their uniforms have been donated by colleagues in France and Belgium. 'There are times we lack basic supplies like hoses,' he said. Volunteer Forest Firefighters Rescue Team member Panagiotis Mastoris, 38, checking a hose during a patrol in Ekali, northern Athens. — Reuters In 2021, just two weeks before a massive fire burned outside Athens, Dertilis said they could not afford to insure all four trucks until private donors stepped in. Then, the fire destroyed their hoses and they searched for donations while flames still burned. Over the years, the team members have bonded like brothers and sisters, but usually it is the thought of their own families that reminds them not to take unnecessary risks. Marinelis' wife Mariana Pilou, an architect, is also a volunteer on the team. They have two young daughters and try to avoid deploying to the same blaze. Pilou, 53, recalled one recent incident: 'It was a difficult situation and the moment I had to run I thought of my kids and I said ... don't act like a hero.' — Reuters
The Star
2 days ago
- The Star
Cricket-Spin could be major factor in WTC final, says Australia's Smith
Cricket - World Test Championship Final - Australia Press Conference - Lord's Cricket Ground, London, Britain - June 9, 2025 Australia's Steve Smith during the press conference Action Images via Reuters/Andrew Boyers LONDON (Reuters) - Australia batter Steve Smith expects spin to play a significant role in this week's World Test Championship final at Lord's as London basks in dry weather ahead of Wednesday's start. Australia defend their title against a South African side making a first appearance in the final on what could be dryer than usual pitch at Lord's and where the seam attacks are expected to dominate. "I think spin will play a big part, particularly as the game wears on," Smith told a press conference on Monday. "We've only been here a week, but I think it's been pretty dry start to the season over here. There hasn't there been too much rain, which is rare for England. "It does look like quite a dry surface and I think the footmarks will definitely come into play as the game wears on." Smith, who is expected to bat at number four, has enjoyed success at Lord's with a double century in the Ashes a decade ago and another ton against England two years ago. "It takes a little bit of time getting used to the slope on the one end," he said. "You feel like you're falling over a little bit while at the other end you feel quite tall. "It takes a couple of deliveries just to get used to that from both ends. I think each time you play out here, you certainly get value for your shots, particularly hitting the ball down the hill. It races away, so it can be a nice wicket to bat on as we've seen over the years as well." Conditions, however, can change quickly in England. "If there's a bit of cloud about and the balls swing around, it can get tricky," Smith said. "Batting on this surface is about just summing it up and playing what's in front of you and being able to adapt accordingly." Australia have not had much practice in the game's first-class format over recent months. "All the batters feel like they're in a good place, so now just excited to go out and play. Lord's is a place we traditionally played pretty good cricket, so we're excited about the prospect of coming up against South Africa," Smith added. (Editing by Ed Osmond)
The Star
04-06-2025
- The Star
Tennis-Keys has no regrets after errors prove costly in French Open quarter-final
PARIS (Reuters) -A litany of errors ended the chances of Madison Keys in her French Open quarter-final with fellow American Coco Gauff on Wednesday but the Australian Open champion said she had no regrets for poor decisions that proved costly. Keys, the newest member of the Grand Slam winners' club following her Melbourne triumph in January, bowed out of Roland Garros after a 6-7(6) 6-4 6-1 loss with her 60th and final unforced error on match-point of a forgettable clash. The affable 30-year-old had arrived in Paris after a less than ideal run in tune-up tournaments on clay and was pleased at making the last eight after showcasing her free-swinging tennis in earlier rounds. "I don't really have regrets. I don't think I played quite the level that I wish that I could have, but I don't think that I regret not going for things or making poor decisions," Keys told reporters. "I just think that what I wanted to do and the level I produced just weren't on the same page today." Keys said playing under the roof of Court Philippe Chatrier on a cold and rainy day made a difference. "Definitely a different environment to play in. A lot more dead and slow with the roof closed," Keys added. "So just very different conditions. I'd much prefer it to be bouncy and hot, but it's just the reality of weather. Conditions like today unfortunately I think play a little bit more into Coco and make her even tougher to beat. "The court being a little bit slower coupled with the fact that she covers the court so well, it just put a little bit of pressure on me to go a little bit more for my shots and maybe press a little bit too much too soon." The big-hitting Keys will welcome the switch to the grass season ahead of Wimbledon, which begins on June 30, even if the turnaround is quick. "The tennis season doesn't really allow you to ease into anything, so I'm going to London tomorrow, and I imagine I'll be on grass on Friday. That's the reality of the sport," she said. "I've typically felt pretty comfortable on grass, so the first couple of days I imagine I'll be a little bit more sore just because the ball is so much lower, and it feels like you have to work a little bit harder just to move on the grass." (Reporting by Shrivathsa Sridhar in Paris; Editing by Andrew Cawthorne)
