However, paleotempestological research allows reconstruction of pre-historic hurricane activity trends on timescales of centuries to millennia. A theory has been postulated that an anti-phase pattern exists between the Gulf of Mexico coast and the Atlantic coast. During the quiescent periods, a more northeasterly position of the Azores High would result in more hurricanes being steered towards the Atlantic coast. During the hyperactive period, more hurricanes were steered towards the Gulf coast as the Azores High—controlled by the North Atlantic Oscillation—was shifted to a more southwesterly position near the Caribbean. In fact, few major hurricanes struck the Gulf coast during 3000–1400 BC and again during the most recent millennium; these quiescent intervals were separated by a hyperactive period during 1400 BC and 1000 AD, when the Gulf coast was struck frequently by catastrophic hurricanes and their landfall probabilities increased by 3–5 times. On the Atlantic coast, chance of landfalling hurricanes has doubled in the recent millennium compared to the one and a half millennia before.