MANILA — A firm based in Florida conducting satellite imagery analysis has published a report this February showing what appeared to be movement and structural changes on Chinese-occupied Mischief Reef in the disputed West Philippine Sea.

The development, an expert said, could indicate further construction operations on the artificial island, known in the Philippines as Panganiban Reef, in the days to come.

The West Philippine Sea is the Philippines' exclusive economic zone in the South China Sea, which China claims in near entirety.

In their February 2021 report titled “New Construction on Mischief Reef,” the firm Simularity pointed to significant changes in 7 areas of Mischief Reef. The movement also seemed to have occurred in late 2020, despite the COVID-19 pandemic.

An area that the company labelled Site Number 1 appeared bare and vacant on May 7, 2020. But another photo of the same area on Feb. 4, 2021 showed the area with standing roofed structures, and the “construction of a permanent cylindrical structure 16 meters in diameter that started in early December 2020.”

The company said that this was “a possible antennae mount structure.”

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Simularity’s reports used “AI-driven satellite imagery anomaly detection” processed by “human geospatial intelligence analysts,” and said it enables them to monitor and release information on the South China Sea on a weekly basis.

Meanwhile, Site Number 2 was pictured on May 7, 2020 as an area full of large rectangular structures that resemble either containers or housing. On Feb. 4, 2021, however, the same area was cleared of the rectangular structures.

Simularity’s partner company, AllSource, also observed a “structure; a concrete structure with a large radome cover” in the same space.

Screengrab from Simularity's report

Screengrab from Simularity's report

Sites Number 4 and 7 were also large sections of the island that had rectangular structures stacked as of May last year, but had been cleared in early February.

Site Number 5, on the other hand, “appears to be a new area of possible construction portside, started between October 22 and Nov. 23, 2020,” according to AllSource.

The report added that “there appears to be construction equipment and a raised, rectangular area constructed adjacent to the port quay.” The same can be said of Site Number 6.

The Asia Maritime Transparency Initiative (AMTI), a Washington-based think tank that has been releasing satellite images of the South China Sea since 2013, also has a 2020 photograph of Mischief Reef that showed changes and additions in the structures from 2017 to 2020.

Mischief Reef is the largest among the seven artificial islands built by China in the Spratlys, and lies within the 200-nautical mile exclusive economic zone of the Philippines.

The Permanent Court of Arbitration ruled in 2016 that Mischief Reef is part of the Philippine continental shelf.

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It was first occupied by China in 1995 through the construction of wooden barracks that they claimed were shelters for fishermen. It is now a 550-hectare air and naval outpost, capable of housing and deploying military assets and conducting surveillance over the West Philippine Sea.

Six other large artificial islands have been built by China in the South China Sea in the last 10 years, with construction accelerated during the height of the Philippines’ filing of a case against China’s maritime incursions before the arbitral tribunal in The Hague.

‘AREA BEING PREPARED FOR MORE BUILDINGS’

Dr. Jay Batongbacal, Director of the Institute for Maritime Affairs Law of the Sea in the University of the Philippines, believes that the newly cleared areas are either “being prepared for more buildings later this year, or those areas are simply holding [or] storage areas awaiting the next batch of supplies.”

Mischief Reef, now with its own airstrip, deep anchorage ports, and radars, is less than 26 nautical miles from Ayungin Shoal (Second Thomas Shoal), where the Philippine government ran the old ship BRP Sierra Madre aground to serve as its military outpost in that section of the West Philippine Sea.

The decrepit, rust-eaten vessel is now where Philippine troops are positioned, between mainland Palawan and the fleet and islands of China out at sea.

While the two countries’ military outposts are geographically fronting the other, Batongbacal said the comparison ends there.

“No comparison with Ayungin [Shoal]. Mischief Reef is so huge, this activity gives one a sense of it,” he explained.

“Also in terms of scale, Mischief Reef is clearly capable of large-scale and probably over-the-horizon surveillance, in addition to being a naval and air base. BRP Sierra Madre is just a garage guardhouse in comparison to that,” he added.

The arbitration court in 2016 rejected Beijing's historic claims to most of the South China Sea, acting on the case lodged by the administration of then President Benigno Aquino III after a standoff between Chinese coast guard ships and a Philippine naval vessel in the Scarborough Shoal.

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Beijing has already undertaken reclamation work on six other reefs it occupies in the Spratlys, expanding land mass five-fold, aerial surveillance photos show. Images seen by Reuters last year appeared to show an airstrip and sea ports.

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— With a report from Reuters