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Post by Admin on Nov 16, 2019 18:36:06 GMT
(Top) InSAR data in ascending and descending orbits depicting surface deformation associated with the 2017 nuclear test. (Bottom) Comparison of the source location of the 2017 nuclear test estimated from this study (red star) with other estimations. Topography along profile CD showing the cavity, deformation zone and probable location of tunnel. Note that the sizes of the cavity and deformation zones are exaggerated by 5 times for better visualization. Credit: K.M. Sreejith / Space Applications Centre / Indian Space Research Organisation Dr. Sreejith and his team turned to space for a solution. Using data from the ALOS-2 satellite and a technique called Synthetic Aperture Radar Interferometry (InSAR), the scientists measured the changes on the surface above the test chamber resulting from the September 2017 explosion, sited at Mount Mantap in the northeast of North Korea. InSAR uses multiple radar images to create maps of deformation over time, and allows direct study of the sub-surface processes from space. The new data suggest that the explosion was powerful enough to shift the surface of the mountain above the detonation point by a few meters, and the flank of the peak moved by up to half a meter. Analyzing the InSAR readings in detail reveals that the explosion took place about 540 meters below the summit, about 2.5 kilometers north of the entrance of the tunnel used to access the test chamber. Based on the deformation of the ground, the ISRO team predicts that the explosion created a cavity with a radius of 66 meters. It had a yield of between 245 and 271 kilotonnes, compared with the 15 kilotonnes of the ‘Little Boy’ bomb used in the attack on Hiroshima in 1945. Lead author of the study, Dr. Sreejith, commented, “Satellite based radars are very powerful tools to gauge changes in earth surface, and allow us to estimate the location and yield of underground nuclear tests. In conventional seismology by contrast, the estimations are indirect and depend on the availability of seismic monitoring stations.” The present study demonstrates the value of space-borne InSAR data for measurement of the characteristics of underground nuclear tests, with greater precision than conventional seismic methods. At the moment though nuclear explosions are rarely monitored from space due to a lack of data. The team argues that currently operating satellites such as Sentinel-1 and ALOS-2 along with the NASA-ISRO Synthetic Aperture Radar (NISAR) mission, due to launch in 2022, could be used for this purpose. Reference: ” Constraints on the location, depth and yield of the 2017 September 3 North Korean nuclear test from InSAR measurements and modelling” by K M Sreejith, Ritesh Agrawal and A S Rajawat, 9 October 2019, Geophysical Journal International. DOI: 10.1093/gji/ggz451
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Post by Admin on Nov 18, 2019 18:55:32 GMT
North Korea on Monday responded to a tweet by U.S. President Donald Trump that hinted at another summit with North Korean leader Kim Jong Un, saying it has no interest in giving Trump further meetings to brag about unless it gets something substantial in return. The statement by Foreign Ministry adviser Kim Kye Gwan is the latest call by North Korea for U.S. concessions ahead of an end-of-year deadline set by Kim Jong Un for the Trump administration to offer mutually acceptable terms for a deal to salvage nuclear diplomacy. Following a U.S. decision over the weekend to call off joint military exercises with South Korea to create space for diplomacy with the North, Trump in a tweet urged Kim Jong Un to “act quickly, get the deal done” and hinted at another summit between them, saying “See you soon!” But Kim Kye Gwan reiterated his government’s stance that Washington must discard what North Korea sees as “hostile” policies to keep the negotiations alive. “Three rounds of DPRK-U.S. summit meetings and talks were held since June last year, but no particular improvement has been achieved in the DPRK-U.S. relations ... the U.S. only seeks to earn time, pretending it has made progress in settling the issue of the Korean Peninsula,” he said in a statement carried by the official Korean Central News Agency, referring to North Korea by the initials of its formal name, the Democratic People’s Republic of Korea. “We are no longer interested in such talks that bring nothing to us. As we have got nothing in return, we will no longer gift the U.S. president with something he can boast of, but get compensation for the successes that President Trump is proud of as his administrative achievements.”
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Post by Admin on Nov 29, 2019 17:44:22 GMT
According to South Korea’s military, the North Koreans fired two short-range projectiles into the sea off its east coast on Thursday. North Korean media reported that Kim was greatly satisfied with the missile launch. Pyongyang’s official KCNA news agency said: ”The volley test-fire aimed to finally examine the combat application of the super-large multiple launch rocket system proved the military and technical superiority of the weapon system and its firm reliability. He warned that if there is no tangible progress, then North Korea could take a “new path,” raising concerns it may resume nuclear and long-range missile testing suspended since 2017. U.S. top nuclear negotiator Stephen Biegun said last week the year-end deadline was an artificial one, but could mean a return to “provocative” steps that preceded the past two years of diplomacy. Analysts believe that the increase in hostile rhetoric by the Kim administration is a sign that the supreme leader is desperate to finally deliver on a promise to his people to lift sanctions and rebuild the country’s ailing economy. They claim that North Korea’s increasingly urgent statements are designed to pressure Washington to return to the negotiating table with a more flexible proposal.
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Post by Admin on Nov 29, 2019 23:19:41 GMT
Kim Hyung-ki, a former vice unification minister of South Korea, told a forum that:”“The North Koreans are telling the United States: ‘We will have to do something very bad unless you do something for us by the end of the year, so please help us stop ourselves.’” However, Robert L. Carlin, a former nuclear negotiator at the State Department and longtime North Korea observer, fears that the situation is extremely precarious and time is running out to solve the situation. Last month talks between the US and North Korea over denuclearisation broke down in acrimony. Officials from North Korea and the US had met for talks in Sweden at the beginning of October in an effort to thrash out an agreement. They met on an island north-east of Stockholm called Lidingo, where North Korea has its embassy. However, the Koreans, led by their top nuclear envoy Kim Myong Gil, left the meeting early and later issued an angry statement saying that the US side had brought "nothing to the negotiation table" and needed to get rid of their "hostile policy" toward Pyongyang. A day after the meeting, the North Korean Central News Agency published a statement giving the Americans a deadline until the end of the year to find a workable solution. The statement read: “As we have clearly identified the way for solving the problem, the fate of the future DPRK-U.S. dialogue depends on the U.S. attitude, and the end of this year is its deadline.”
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Post by Admin on Nov 30, 2019 21:00:35 GMT
North Korea has branded Japan's PM Shinzo Abe an "imbecile" and "political dwarf", accusing him of mislabelling its latest weapons test. Mr Abe condemned the North for "repeated launches of ballistic missiles" after two projectiles were fired on Thursday. But the North insisted it was testing a "super-large multiple-rocket launcher". On Saturday, state media said Japan "may see what a real ballistic missile is in the not distant future". North Korea is banned from firing ballistic missiles under UN Security Council resolutions. The country is under various sets of sanctions over its missile and nuclear programmes. Lifting the sanctions has been a key aim of the North in talks with the US - Japan's ally - but these have stalled since a summit between its leader Kim Jong-un and President Donald Trump broke down in February.
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