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Roger M. Waller

Publications and source records attributed to Roger M. Waller.

8 recordsLinked to original sources
USGS1969

The Alaska earthquake, March 27, 1964: Effects on communities

This is the second in a series of six reports that the U.S. Geological Survey published on the results of a comprehensive geologic study that began, as a reconnaissance survey, within 24 hours after the March 27, 1964, Magnitude 9.2 Great Alaska Earthquake and extended, as detailed investigations, through several field seasons. The 1964 Great Alaska earthquake was the largest earthquake in the U.S. since 1700. Professional Paper 542, in 7 parts, describes the effects of the earthquake on Alaskan communities.

Alaska↗
USGS1966

Effects of the earthquake of March 27, 1964, in the Homer area, Alaska

The March 27, 1964, earthquake shook the Homer area for about 3 minutes. Land effects consisted of a 2- to 6-foot subsidence of the mainland and Homer Spit, one earthflow at the mouth of a canyon, several landslides on the Homer escarpment and along the sea bluffs, and minor fissuring of the ground, principally at the edges of bluffs and on Homer Spit. Hydrologic effects consisted of at least one and possibly two submarine landslides at the end of the spit, seiche waves in Kachemak Bay, ice breakage on Beluga Lake, sanding of wells, and a temporary loss of water in some wells. Seismic damage to the community was light in comparison with that of other communities closer to the epicenter. One submarine landslide, however, took out most of the harbor breakwater. The greatest damage was due to the subsidence of the spit, both tectonically (2–3 ft) and by differential compaction or lateral spreading (an additional 1–4 ft). Higher tides now flood much of the spit. The harbor and dock had to be replaced, and buildings on the end of the spit had to be elevated. Protection works for other buildings and the highway were needed. These works included application of fill to raise the highway and parts of the spit above high tides. Reconstruction costs and disaster loans totaled about $2½ million, but this amount includes added improvement costs over preexisting values. Homer Spit in particular and the Homer area in general rank as areas where precautions must be taken in selecting building sites. The hazards of landslides, earthflows, compaction and submarine slumping—all of which might be triggered by an earthquake—should be considered in site selection. In plan, Homer Spit resembles a scimitar with its curving blade pointed seaward. It is about 4 miles long and as much as 1,500 feet wide. The spit is composed largely of gravel intermixed with some sand. After the earthquake and the resulting tectonic subsidence and compaction, much of the spit was below high-tide levels and consequently flooded periodically. The entire beach face has retreated. Much of the material eroded from the beach has been redeposited to form a new storm or frontal berm, locally migrating around buildings and covering roads. Beach recession of 10–15 feet is probably the overall average; maximum recession 1 year after the earthquake was 56 feet along one limited section of the distal end of the spit. Subsidence of the mainland has caused accelerated erosion of the beaches and headlands that have been—and are—source areas for the material deposited on Homer Spit. The resulting increased supply of gravel and sand probably will cause the spit to widen gradually on the Cook Inlet side. Similarly, the new frontal berm will probably grow to a height sufficient to prevent overtopping by all but the larger storm swashes. The nature of shore processes on the spit has not been materially altered by subsidence, but the rates of erosion and deposition have been accelerated. The lasting effect of subsidence (excluding flooding) will be enlargement of the beach on the Cook Inlet side and gradual wasting of the beach on the bay side of the spit.

Alaska↗
USGS1966

The Alaska earthquake, March 27, 1964: effects on hydrologic regimen

This is the fourth in a series of six reports that the U.S. Geological Survey published on the results of a comprehensive geologic study that began, as a reconnaissance survey, within 24 hours after the March 27, 1964, Magnitude 9.2 Great Alaska Earthquake and extended, as detailed investigations, through several field seasons. The 1964 Great Alaska earthquake was the largest earthquake in the U.S. since 1700. Professional Paper 544, in 5 parts, describes the effects on hydrologic regimen.

Alaska↗
USGS1966

Effects of the March 1964 Alaska earthquake on the hydrology of south-central Alaska

The earthquake of March 27, 1964, greatly affected the hydrology of Alaska and many other parts of the world. Its far-reaching effects were recorded as water-level fluctuations in gages operated on water wells and streams. The close-in effects were even more striking, however; sediment-laden ground water erupted at the surface, and even ice-covered lakes and streams responded by seiching. Lake and river ice was broken for distances of 450 miles from the epicenter by seismic shock and seiche action. The surging action temporarily dewatered some lakes. Fissuring of streambeds and lakeshores, in particular, caused a loss of water, and hydrologic recovery took weeks in some places. Landslides and snow avalanches temporarily blocked streams and diverted some permanently. The only stream or lake structures damaged were a tunnel intake and two earthen dams. The winter conditions-low stages of water and the extensive ice cover on lakes and streams-at the time of the earthquake greatly reduced the damaging potential. Ground water was drastically affected mostly in unconsolidated aquifers for at least 160 miles from the epicenter. Within 100 miles of the epicenter, vast quantities of sediment-laden water were ejected in most of the flood plains of the glaciofluvial valleys. A shallow water table and confinement by frost seemed to be requirements for the ejections, which were commonly associated with cratering and subsidence of the unconsolidated material. Subsidence was also common near the disastrous submarine landslides, and was probably caused by loss of water pressure and by lateral spreading of sediments. Effects on ground water in bedrock were not determinable because of lack of data and accessibility, particularly within 50 miles of the epicenter. Deep aquifers in unconsolidated sediments, which in most areas are under high hydrostatic pressure, were also greatly affected. Postearthquake water levels for a year were compared with long-term prequake levels to show permanent changes in an aquifer system. At Anchorage and in parts of the kenai Peninsula, artesian-pressure levels dropped as much as 15 feet. These lower pressures were probably caused either by grain rearrangement which increased the porosity within the aquifer or by a displacement of material that allowed water to discharge more freely at the submarine terminus of the aquifer. Seismically induced pressure on ground water was instrumental in causing most of the disastrous slides. Water quality was not changed except for temporary increases in turbidity in wells and streams. The sediment load in streams during the April spring run-off appeared to be greatly increased over previous years.

Alaska↗
USGS1966

Effects of the March 1964 Alaska earthquake on the hydrology of the Anchorage area, Alaska

The Anchorage hydrologic system was greatly affected by the seismic shock. Immediate but temporary effects included increased stream discharge, seiche action on lakes, and fluctuations in ground-water levels. Generally, ground-water levels were residually lowered after the initial period of fluctuation. This lowering is attributed either to changes in the discharge zones offshore or to a change in the permeability of the aquifers by seismically induced strain. Water supplies were disrupted temporarily by snowslides on streams and by sanding or turbidity in wells. Salt-water encroachment to wells on Fire Island seems to have increased. The approximate 3.7-foot lowering of land level and the diminished artesian head may permit further salt-water encroachment. Increased pore pressure in the Pleistocene Bootlegger Cove Clay led to liquefaction in silt and sand lenses that contributed to the disastrous bluff landslides. Measurements after the earthquake indicate that most pore pressures are declining, whereas some remain high or are increasing. Subsidence in the area was caused principally by tectonic readjustment, but differential compaction within the Bootlegger Cove Clay contributed to subsidences estimated to be as much as 0.6 foot beneath Anchorage.

Alaska↗