An earthquake with a magnitude of 3.9 has struck in the middle of the English Channel, the British Geological Survey (BGS) has said.
Residents in parts of West Sussex reported buildings shaking for a few seconds but no injuries or damage has been reported.
The quake struck at 7.59am, had a depth of 10km and its epicentre was around 85km south-east of Portsmouth, Hampshire, according to the BGS.
It was the largest earthquake in the area for almost 300 years. One worker said it felt like a "big lorry had gone by in a hurry".
Hampshire Police, Sussex Police, Solent Coastguard, Hampshire Fire and Rescue Service and West Sussex Fire and Rescue Service said they had not been called to incidents related to it.
David Kerridge, from the BGS, said: "This is the largest earthquake in this area since a magnitude 4.5 event in 1734. Historically, there have been two other significant events nearby - a magnitude 5.0 earthquake in 1878 and a magnitude 4.3 earthquake in 1750.
"In the UK, we experience a earthquake of this magnitude approximately every two years."
Brian Baker, data manager at the Sussex Safer Roads Partnership, felt the earthquake in his office on the coast in Shoreham, near Brighton.
He said: "The office wobbled slightly, the building shook, monitors on the table rattled and the roof creaked a bit. It lasted about two to three seconds. There was no damage as far as we can see.
"It felt as if a big lorry had gone by in a hurry, except we don't have lorries go through here."