impact of "debris" the size of the first section

that's the timeline given after explosions

freelance journalist from Denmark, Niels Eriksen reports:
"U.S. Torpedo Appeared at Explosion Site of the Nord Stream".
40-year-old motive, one destroyer, "200 hrs" of stealth seabed surveys over 9 months, master "underwater fast attack" commander, one Harpoon "tested on the battlefield in Ukraine", Guardian rendered "approximate location" of four (4) leaks, AND

the remains of the American torpedo near the Nord Stream pipeline explosion site,
computer image taken from hidden camera

Wired | 'Dark Ships' Emerge From the Shadows of the Nord Stream Mystery, 11 Nov

According to the analysis by satellite data monitoring firm SpaceKnow, the two "dark ships," each measuring around 95 to 130 meters long, passed within several miles of the Nord Stream 2 leak sites. "We have detected some dark ships, meaning vessels that were of a significant size, that were passing through that area of interest," says Jerry Javornicky, the CEO and cofounder of SpaceKnow.

where?

"They had their beacons off, meaning there was no information about their movement, and they were trying to keep their location information and general information hidden from the world," Javornicky adds.

The discovery, which was made by analyzing images from multiple satellites, is likely to further increase speculation about the cause of the blasts....Once SpaceKnow identified the ships, it reported its findings to officials at NATO, who are investigating the Nord Stream incidents. Javornicky says NATO officials asked the company to provide more information.

when?

NATO spokesperson Oana Lungescu says it does not comment on the "details of our support or the sources used" but confirmed that NATO believes the incident was a "deliberate and irresponsible act of sabotage" and it has increased its presence in the Baltic and North Seas. However, a NATO official, who did not have permission to speak publicly, confirmed to WIRED that NATO had received SpaceKnow's data and said satellite imagery can prove useful for its investigations.
[...]
To detect the ships, Javornicky says, the company scoured 90 days of archived satellite images for the area....Once it gathered archive images of the area, SpaceKnow created a series of polygons around the gas leak sites. The smallest of these, around 400 square meters, covered the immediate blast area, and larger areas of interest covered several kilometers. In the weeks leading up to the explosions, SpaceKnow detected 25 ships passing through the region, from "cargo ships to multipurpose larger ships," Javornicky says.  In total, 23 of these vessels had their automatic identification system (AIS) transponders turned on. Two did not have AIS data turned on, and these ships passed the area during the days immediately ahead of the leaks being detected.

27.09.22 Berlingske video "area of interest" d: 1km, 2 jet NS1 leak  (src: Norwegian Defense Command)