Category 4 severe tropical cyclone (Aus scale) | |
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Satellite image of Cyclone Althea on 23 December
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Formed | 19 December 1971 |
Dissipated | 29 December 1971 |
Highest winds |
10-minute sustained: 165 km/h (105 mph) |
Lowest pressure | 952 hPa (mbar); 28.11 inHg |
Fatalities | 2 direct, 1 indirect |
Damage | $120 million (1971 AUD) |
Areas affected | Queensland |
Part of the 1971–72 Australian region cyclone season |
Severe Tropical Cyclone Althea was a powerful tropical cyclone that devastated parts of North Queensland just before Christmas 1971. One of the strongest storms ever to affect the Townsville area, Althea was the fourth system and second severe tropical cyclone of the 1971–72 Australian region cyclone season. After forming near the Solomon Islands on 19 December and heading southwest across the Coral Sea, the storm reached its peak intensity with 10-minute average maximum sustained winds of 165 km/h (105 mph) – Category 4 on the Australian cyclone scale. At 09:00 AEST on Christmas Eve, Althea struck the coast of Queensland near Rollingstone, about 50 km (30 mi) north of Townsville. Although early weather satellites provided only occasional glimpses into the cyclone's formative stages, its landfall was monitored closely by land-based radar that depicted an ongoing eyewall replacement cycle. Althea produced copious rainfall over central and western Queensland as it turned toward the southeast, and on 26 December the cyclone emerged over open waters. After briefly re-intensifying, the system dissipated on 29 December.
While moving ashore, Althea generated wind gusts as high as 215 km/h (134 mph) that wrought significant destruction around Townsville and left nearby Magnetic Island in a state of ruin; almost all of the buildings on the island were damaged to some degree. A significant 3.66 m (12.0 ft) storm surge battered the mainland, while high waves destroyed roads and seawalls. Beaches receded by up to 15.8 m (52 ft) due to coastal erosion. In Townsville, thousands of homes were damaged and many were destroyed. The most widespread damage was to roofs, which were often poorly or not at all secured. The damage from Althea prompted Queensland to develop its first state-wide building codes, requiring new homes to be cyclone-resistant. Townsville was the first community to adopt the enhanced construction standards. In addition to the coastal effects, Althea triggered extensive river flooding in interior Queensland. Most major roads in western portions of the state were cut off by floodwaters, and hundreds of families had to leave their homes for higher ground. In the aftermath of the cyclone, 600 Australian Army soldiers aided recovery efforts in Townsville and Magnetic Island, while both state and federal governments contributed disaster relief funds. Three people were killed and damage totaled $120 million (1971 AUD).