According to the Irish National Seismic Network (INSN), seismometers picked up the "explosion-like" event approximately 11 minutes after the test.
Tom Blake, the network's director, said that the explosion from the nuclear test propagated through the ground measuring 4.9 magnitude on the Richter Scale.
State media in North Korea said the country had successfully detonated a "miniaturised" nuclear device in a "safe manner" at a test site in the north east of the country.
It said the test was aimed at coping with what they called "outrageous" US hostility that "violently" undermined their rights to launch satellites.
This is the state's first nuclear test since leader Kim Jong Un took power in December 2011 following the death of his father, Kim Jong Il.
A country long estranged from the West, experts say regular tests are needed to perfect North Korea's goal of building nuclear warheads small enough to be placed on long-range missiles.
The atomic test - North Korea's third since 2006 - is expected to take the capital Pyongyang closer to possessing nuclear-tipped missiles designed to strike the United States.
Tom Blake is also Head of the National Data Centre, Comprehensive Nuclear Test Ban Treaty Organisation at the Dublin Institute for Advanced Studies (DIAS).
Our data suggests the test was a more powerful blast than North Korea's two previous tests.
"The energy wave generated by North Korea's nuclear test was clearly picked up by seismometers in north Donegal and the Dublin Mountains approximately 11 minutes after it occurred at 2:58 AM (GMT) on Tuesday," he said.
"It was located roughly in the region of the previous North Korean nuclear tests of 2006 and 2009. The South Korean defence ministry has provided preliminary yield estimates for the test of between 6 to 7 kilotons."
Mr Blake said seismometers are so sensitive that they can easily pick up strong seismic activity on the other side of the world.
This latest test has been met with widespread condemnation from the international community.
Foreign Secretary William Hague called the action a "violation of United Nations Security Council resolutions".
"North Korea's development of its nuclear and ballistic missile capabilities poses a threat to international and regional security. Its repeated provocations only serve to increase regional tension, and hinder the prospects for lasting peace on the Korean Peninsula."
Mr Hague said UN resolutions committed the security council to taking "significant action" in the event of a further launch or nuclear test by North Korea.
"The UK will begin urgent consultations with security council partners calling for a robust response to this latest development," he said.
"North Korea has a choice to make - it can either engage constructively with the international community, cease developing its nuclear and ballistic missile programmes and return to negotiations, or face increasing isolation and further action by the security council and the international community."
Eamon Gilmore, Irish Minister for Foreign Affairs, described the action as "reckless and provocative".
"I condemn, in the strongest possible terms, the test by North Korea of a nuclear explosive device.
"This action threatens peace and stability on the Korean peninsula. It is also a major challenge to our efforts to advance global nuclear disarmament and non-proliferation, a longstanding priority of Irish foreign policy," the Tánaiste added.
"Nuclear weapons are never a means to guarantee peace and security; far from it, they pose the greatest threat of all.
"The regime in Pyongyang must realise that today's act is reckless and provocative and will only isolate it further from the international community."
The UN Security Council held an emergency meeting in New York on North Korea's nuclear test on Tuesday afternoon.
US President Barack Obama called the move a "highly provocative act" that threatens US security and international peace.
In a statement President Obama promised to "continue to take steps necessary to defend ourselves and our allies."
He also urged "swift and credible action by the international community."
The president said North Korea has "increasingly isolated and impoverished its people through its ill-advised pursuit of weapons of mass destruction."