NATURAL HAZARDS on the Island of Hawaii

United States Department of the Interior/Geological Survey HUALALAI HAWAII

MAUNA LOA

\ *'* ATURAL HAZARI?? on the Island of Hawaii

I he island of Hawaii and the other waii are well known. They can be en­ islands of the Hawaiian chain are prod­ hanced by recognizing and realistically ucts of volcanic eruptions. Lava flows considering the existing hazards. from hundreds of thousands of eruptions This booklet discusses some common through countless centuries have built questions about some natural hazards the Hawaiian Islands. Some volcanoes on the island of Hawaii. The replies are on the island of Hawaii have been very brief and generalized; further informa­ active during historic time, and similar tion may be obtained from one or more activity is expected to continue through­ of the references listed at the end of out the foreseeable future. this booklet. Volcanoes have always been an im­ portant element in the lives of Hawaii's 1. How great are the hazards from Ha­ inhabitants. Volcanic rocks are the raw waii's volcanoes? materials from which the rich soils are The hazards are severe enough to derived that are the basis of Hawaii's have caused property losses on certain largest industry agriculture. Tourism, parts of the island throughout Hawaiian the island's second largest industry, also recorded history. The village of Hoopu- benefits from the volcanoes; the erup­ loa on Mauna Loa's west flank was tions provide unsurpassed spectacles buried by a lava flow in 1926. Much that attract visitors. property in the Puna District was de­ Hawaiian volcanic activity, however, stroyed by flows in 1955, and even more as well as other natural events such as property, including the village of Ka- earthquakes and tsunamis (earthquake- poho, was destroyed by flows in 1960. triggered sea waves), can be hazardous to In spite of such losses, most areas on people and property. Even though no the island have been free of damage. place on Earth is immune from some sort Thus, it is crucial to identify the haz­ of natural hazard, the island of Hawaii ardous areas to avoid losses without has its own individual blend. But when overreacting to danger. Generally there the hazards are clearly recognized, care­ is very little direct danger to human life, ful planning can minimize any possible but the risk to property is great enough disturbance and damage. The benefits that volcanic hazards should be consid­ of living, working, and visiting in Ha­ ered in all plans for land use even though such consideration for many members cTf a traveling Hawaiian army. places will quickly determine that the Another explosive eruption in 1924 risk is low. threw large blocks of rock into the air Hawaii has been inhabited for per­ and claimed the life of a spectator who haps a thousand years, and people have failed to heed warnings to leave. But the lived successfully beside and on the ac­ overall threat to life by explosive erup­ tive volcanoes. The early Hawaiians tions is relatively low, both because of quickly learned, however, to adjust their their infrequency and because of warn­ lives to the threat of volcanic activity. ings. They either avoided certain areas or entered them briefly with awe and re­ spect. Even so, their activities were 4. How may volcanic events endanger sometimes abruptly curtailed by lava property? flows and other effects of volcanic ac­ The principal effect is the burial of tivity. Recent residents of Hawaii have land and the works of man by flowing had similar experiences. They, too, rec­ lava. Less commonly, property may be ognize that certain areas are particularly blanketed by falling spatter from foun­ susceptible to volcanic disturbances. tains or by ash and larger fragments ex­ Many of these areas have never been pelled by rare explosive eruptions. inhabited, but as the population in­ Other effects include the damage to creases, the desire to move into pre­ buildings and roads caused by ground viously little used or unused land in­ cracking, corrosion of materials by vol­ creases. Under the pressures of a growing canic gases, fires started by lava, and population and expanding economy abrasion of plants and goods by erupted especially during prolonged lulls in vol­ particles. Risks to property are high com­ canic activity the potential hazards tend pared with risks to life, simply because to be forgotten or underestimated. land and buildings cannot be moved from the path of an advancing flow or other destructive agent. Destruction of 2. What kinds of hazards do the vol­ the works of man and agricultural soils canoes present? by a flow of lava can be complete, Lava flows are the most common vol­ whereas damage from particles and canic hazard in Hawaii. Other hazards gases is generally less serious. Reduction include lava spatter, corrosive volcanic of such risks is possible when the haz­ gases, ash particles and rarely explo­ ards are understood well enough to pre­ sions of turbulent clouds of gas that may dict at least in a general way what carry dust, rock fragments, and large areas are most likely to be affected and blocks. Related hazards are ground shifts how often. that cause unequal settling, fractures that break the Earth's surface, and earthquake shaking. 5. Should vulnerable areas be aban­ doned? No. For each area, however, the risks 3. How may volcanic events endanger should be compared with the potential people? gains from developing and using the Eruptions may endanger people's land. Even in areas of relatively high property, livelihood, and peace of mind, risk, certain types of land use may be but seldom their lives. The vast majority appropriate. Many other factors must be of Hawaiian eruptions are gentle; the considered by planners and local gov­ lava moves slowly, and warnings of im­ ernment officials in deciding how land pending eruptions allow people to reach can best serve the needs of the people. places of safety. No human lives have Nevertheless, sensible decisions on land been lost to lava flows during the 19th use can best be reached with full aware­ and 20th centuries. ness and adequate knowledge of the Explosive eruptions are rare in Ha­ nature and degree of natural hazards. waii, but they are potentially lethal. A If the hazards are ignored, the results gas-cloud eruption about 1790, in a can range from inconvenience to catas­ normally uninhabited area, killed many trophe. EXPLANATION

Boundary between volcanoes

Boundary between island districts

Rift zones

Kapoho

Hoopuloa

15 30 KILOMETRES I contour interval: 1,000 feet

Figure 1. Index map of the island of Hawaii.

6. Can eruptions occur anywhere on the dicates that they will be the source of island? most of Hawaii's future eruptions. Probably not. Only two of the island's five volcanoes, Kilauea and Mauna Loa Hualalai Volcano last erupted about (fig. 1) have erupted often during the 1800, and will probably erupt again, but 19th and 20th centuries. The location its history suggests that future eruptions and frequency of past eruptions are the are not likely to be frequent. Mauna Kea best clues as to where new eruptions last erupted between 3,000 and 5,000 are likely to occur, and the present years ago and might possibly erupt behavior of Mauna Loa and Kilauea in­ again. But the probability that it will

Table 1. Physical dimensions of the parts of Hawaii's volcanoes (fig. 1) that are above sea level. Elevation of Area Percent Volcano highest point Square Square of area of Feet Metres miles kilometres island 13,677 4,169 2,035 5,271 50.5 4,090 1,247 552 1,430 13.7 Hualalai ...... 8,271 2,521 290 751 7.2 13,796 4,205 919 2,380 22.8 Kohala ...... 5,480 1,670 234 606 5.8 Total island ...... 4,030 10,438 100 erupt in the near future must be con­ along minor rift zones on Mauna sidered as very small. Kohala's last erup­ Loa have erupted a few times within tion took place about 60,000 years ago, area E. Degree of risk within this area and chances for activity during the next varies widely, but in general, it becomes several decades are virtually nil. Table 1 less with increasing distance from the lists some geographical facts about the summits and major rift zones. five volcanoes. Area DE, Hualalai Volcano. Lava flows have buried land in this area more re­ 7. What areas are most susceptible to cently than in area D. Yet the frequency volcanic hazards? of eruptions of Hualalai is much less The summits and rift zones of Kilauea than Kilauea and Mauna Loa. Moreover, and Mauna Loa are the areas of highest vents are not confined to rift zones. risk. Rift zones are long, narrow belts Risk on Hualalai is rather poorly defined of structural weakness that include because of the sparse historic record, cracks, fissures, craters, spatter cones, but it probably spans a range equiva­ and cinder cones. Kilauea and Mauna lent to those in area D and the low risk Loa each have two major rift zones that parts of area E. extend from the summit to points far Area D includes selected areas on the down the flanks of the volcanoes (fig. 1). flanks of Kilauea and Mauna Loa that Hualalai and parts of the flanks of Ki­ are somewhat protected by topography lauea and Mauna Loa have less risk, from burial by lava. No historic or re­ and Mauna Kea and Kohala are the cent prehistoric flows have invaded areas of least risk. Specific areas have these areas. been outlined to designate relative de­ Area C is the summit region and up­ grees of risk (fig. 2), which increase per flanks of Mauna Kea. The latest progressively from areas marked A eruptions within this area took place through those marked F. between 3,000 and 5,000 years ago. 8. How are volcanic hazard areas desig­ They consisted of small lava flows and nated? moderately explosive emissions of spat­ Volcanic hazard areas are designated ter and particles that built cinder principally by the location and the fre­ cones. Volcanic ash was spread widely quency of past eruptions. Major criteria by air currents. Future eruptions will are listed below; additional information probably be similar, although the erup­ in table 2 is an aid to understanding tive frequency is now so low that the the relative degree of hazard within hazard must be regarded as very small. each of the areas. Area B consists of the lower flanks of Area F, the area of highest risk, in­ Mauna Kea. No eruptions have occurred cludes the summit areas and major rift in this area during the last 10,000 years. zones of Kilauea and Mauna Loa. Most This land could be buried only by rela­ of the land labeled F has a historic and tively long lava flows issuing from vents recent prehistoric record of active vol­ in area C. canic vents, cones, and craters; ground Area A, Kohala Volcano. No volcanic cracking and subsidence; and burial by activity has occurred in this area for lava flows. Narrow coastal regions on about 60,000 years. parts of Kilauea and Mauna Loa are also labeled F because they lie within belts 9. How dangerous are the areas of high of frequently active faults in which the hazards? land is subject to cracking, abrupt sub­ A careful study of figure 2 and table 2 sidence, and possible flooding by locally and their implications is perhaps the generated tsunamis. best way to answer this question. For Area E includes the flanks of Kilauea example, since about 1800 A.D., lava and Mauna Loa that lie directly down- flows from 35 different eruptions have slope from the summit areas and rift covered parts of area E; only one erup­ zones where lava flows originate. Land tion on the north flank of Mauna Loa, labeled E is susceptible to burial by lava in 1859, originated within area E. About flows erupted within the summit and 15 percent of area E has been covered rift areas labeled F. In addition, vents by lava during this 175-year period. In hysical boundary between volcanoes

Approximate judgemental boundary between areas of relative risk

Historic lava flows

Figure 2. Areas of relative risk from volcanic hazards. Risk increases from "A" through "f Map shows lava flows erupted between the years 1800 and 1974.

Table 2. Number of eruptions originating within hazard areas and number of limes lava flows have covered land within hazard areas during historic and recent prehistoric time. Historic time (since Recent prehistoric time approximately 1800) (5,000-year interval prior to 1800) Number of times Number of Number of times Percentage Number of times lava flows have times vents lava flows have of land vents have covered land have erupted covered land covered erupted within within area Area within area within area within area area (estimated) (estimated) A 0 0 0 0 0 B 0 0 0 0 Less than 5 C 0 0 0 Less than 5 Less than 5 D 0 0 0 0 More than 10* DE 1 2 6 More than 10 More than 10 E 1 35* 15 About 10 More than 100* F 80 More than 80 50 About 2,000 More than 2,000 Most lava flows that entered areas D and E erupted from vents in area F. Geological Survey scientists examining hot cinder cone. contrast, during the same period ap­ provides the best clue to future behavior. proximately 80 eruptions originated 10. Once an area has been covered by within area F, and some land within the lava, is it safe from future burial? area was buried by lava during each No, although many people mistakenly eruption. Lava has covered about half of thinkso. The entire island is made up of area F during this period. a succession of lava flows, attesting to Records show that during each 20- repeated stacking of one flow over an­ year period from 1830 to the present, other throughout the volcanic history of between 25 and 75 square miles (65 the island. Some areas near Kilauea's and 195 square kilometres) of land have summit and along the upper east rift been covered by lava. This is approxi­ zone have been covered repeatedly dur­ mately 1 to 3 percent of the region ing the past few years. Recent flows occupied by Kilauea and Mauna Loa. across an area are no guarantee against Area F occupies about one sixth of the future burial. area of Kilauea and Mauna Loa. Yet nearly 40 percent of all land covered by 11. Are the risks uniform within a par­ lava that erupted during historic time ticular hazard area? has been in areas designated F. This in­ No, the risks may be quite variable dicates that roughly 3 to 8 percent of throughout any hazard area, depending the land in area F has been buried dur­ chiefly on the local topography and the ing any given 20-year period. In this distance from potential source vents. For area of highest hazard, roughly 92 to 97 example, the risk is greater on low percent of the land remained free from ground than on higher ground in the lava burial during any specific 20-year same vicinity. Risks tend to be greater period. Similarly, from about 0.5 to 3 on steep slopes than on gentle slopes. percent of the land in area E has been And risks gradually decrease as the dis­ buried during various 20-year intervals, tance from eruptive vents increases. All leaving 97 to 99.5 percent unaffected. of these factors vary throughout each of Although it is not certain that this pattern the designated hazard areas and, in par­ will be maintained, past behavior still ticular, are important for those areas with historic activity. This variability mental factors instead of specific topo­ shows that the classification of hazards graphic features. For example, the des­ is chiefly appropriate when applied to ignation of the outer limits of rift zones the area as a whole. Detailed studies of is subject to considerable interpretation. certain specific sites, however, might The boundaries around areas somewhat suggest a degree of risk either higher or protected from the direct paths of po­ lower than that designated for the area tential lava flows (such as areas marked in which the site falls. D) are designated only by exercising a substantial amount of judgment. The ap­ 12. How are the risks evaluated for land proximate placement of such boundaries close to area boundaries? shows that the degree of risk applicable The risks can change either abruptly to two pieces of property close to each or gradually across area boundaries, de­ other, but on opposite sides of a judg­ pending upon the kind of boundary in­ mental boundary, cannot be considered volved. Abrupt changes in risk occur to be significantly different. Boundaries across boundaries that are determined designated as "judgmental" in figure 2 according to topographic features, such should be regarded as both approximate as the trough formed by the junction of and gradational. the slopes of Mauna Loa and Mauna Kea. The trough itself may be threatened 13. How serious is the earthquake dan­ by lava flows from Mauna Loa, but risk ger on the island? from lava flows only a short distance up Strong earthquakes have occurred in the adjoining flank of Mauna Kea is very the past and can be expected in the low. Thus, a site only a short distance future. The strongest earthquake in his­ on one side of that boundary has an toric time occurred in 1868 and was easily recognized and markedly dif­ centered along the island's south coast ferent risk than a site a short distance on (fig. 3). This earthquake had a Richter the other side of the same boundary. magnitude of about 7 1/z and caused Some area boundaries, however, serious damage across the entire island. have been designated according to judg- Recent quakes caused significant damage

Spatter fountain in eruption. in 1951, 1973, and 1975. Figure 3 shows land. The risk is perhaps most severe in the approximate locations and the dates areas of steep and unstable slopes where of some of the strongest historic earth­ landslides and rockfalls are likely to be quakes on and near the island. The fre­ induced by earthquakes. The risk from quency of these earthquakes and their earthquakes on the island is comparable widespread distribution show that the to that in many regions on the mainland island faces an ever-present possibility United States and elsewhere that have of earthquakes strong enough to cause high seismic hazards. extensive damage. Danger from earthquakes can be mini­ Large earthquakes, unlike volcanic mized by careful site selection and eruptions, are not confined to any par­ proper earthquake-resistant design of ticular part of the island. Furthermore, man-made structures. Such matters as shaking may cause damage far from the the angle and stability of slopes and the point where the quake is centered. For firmness of foundation sites vary widely this reason, it is not feasible to draw an from one locality to another. Competent evaluation of individual sites during "earthquake hazard map" of the island, land-use planning can do much to re­ such as figure 2 that illustrates the vol­ duce earthquake risks. Local officials canic hazards. Risk of major damage have the responsibility of maintaining from strong earthquakes is considered to proper standards of site selection and be relatively high across the entire is­ earthquake-resistant construction.

EXPLANATION 1951 Year ® Location (6.9) Magnitude

30 KILOMETRES

Figure 3. Location of points of origin of major historic Hawaiian eartllquakes whose magnitude exceeded 6. Locations and magnitudes tor earthquakes prior to 1960 are highly approximate because instrumental data are sparse, therefore fractions are used.

10 EXPLANATION Point of origin of earthquakes of magnitude 3 or greater, 1970-1973

Point of origin of earthquake of April 26, 1973, magnitude 6.2

5 30 KILOMETRES

Figure 4.-Points of origin of earthquakes of magnitude 3 or greater on or near Hawaii from 1970 to 1973.

14. Aren't many Hawaiian earthquakes such as those on Kilauea's southwest rift concentrated in certain areas? zone in December 1971 and January Yes. In recent years the greatest num­ 1975, the earthquakes can be conspicu­ ber of earthquakes on the island have ous, annoying, and sometimes frighten­ occurred on or near Kilauea, but earth­ ing. quakes also tend to be concentrated in other specific areas. An example of how earthquakes are concentrated is the map of figure 4, which shows the distribution of earthquakes of larger than magnitude 3 that occurred from 1970 to 1973. Maps for other periods of time may show dif­ ferent distributions. Most of these earth­ quakes are much smaller than the major earthquakes previously discussed, and few caused damage. Of the earthquakes shown in figure 4, only the one of April 26, 1973, caused any significant damage. However, hundreds of those shown in the figure were strong enough to be felt. Thousands more, not shown on this map, were so small that they were de­ tected only by sensitive instruments. Quakes smaller than about magnitude 5, even those that can be felt, do not pose a substantial hazard to life and property. When they occur in swarms, however, Ground failure caused by an earthquake.

11 Damage caused by

15. What is a tsunami? flooding and smashing all in its path. A tsunami is a giant wave or series of While at sea, a tsunami is scarcely no­ waves produced by a large-scale disturb­ ticeable. As the wave enters shallow ance of the ocean floor. "Tsunami" is water or is funnelled into a bay, it can the Japanese name for these waves; the build to great heights. Some have been term "tidal wave" is also used, but it is recorded at more than 100 feet (30 misleading because the waves have no metres) above normal sea level. Reach­ relation to tides. Most tsunamis are gen­ erated by the sudden movement of the ing a shoreline, a tsunami advances in­ ocean floor along a fault a submarine land at velocities of 30 to 60 miles (50 earthquake. Others may be caused by to 100 km) per hour, endangering life abrupt subsidence of the ocean floor or and destroying property. They can be a submarine volcanic eruption. Tsunamis powerful enough to smash buildings and spread outward in all directions from toss anchored ships ashore. As they re­ their source. In the open ocean they cede, people, animals, and property may may travel for thousands of miles at be swept into the sea. A tsunami may speeds of several hundred miles per include several waves, separated by in­ hour. 16. How does a tsunami do damage? tervals of 5 to 40 minutes. Areas that When a tsunami reaches some coast­ escape early waves may be damaged by lines, it may rush ashore at high speeds, those later in the series.

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FXPLANATION

* Tide Stations * Seismograph Stations

Figures. Tsunami Warning System showing reporting stations and tsunami travel times to Honolulu. Concentric circles radiating from Hawaii like a gigantic spider web show seismic sea wave travel times to Honolulu. Reporting stations in the tsunami warning system are encompassed by a great ring bounded by such diverse locales as Alaska, China, and Chile.

17. How serious is the tsunami threat to of 1868 and 1975 were of local origin. Hawaii? The tsunami of 1868, the most severe, Hawaii is vulnerable to destructive devastated the entire southern coast of tsunamis of distant origin, as well as less the island, killing about 80 people and frequent ones that originate close to the destroying several villages. The tsunami island. The Pacific Ocean is ringed by a of 1975 claimed two lives, and although belt of active faults that may cause it caused widespread damage, its strong­ ocean bottom displacements, but, for­ est effects were in uninhabited areas. tunately, few circumpacific earthquakes Tsunamis are a great, though infrequent, generate tsunamis. Since the early 19th danger to both people and property in century, about 40 tsunamis have been coastal regions of Hawaii, perhaps large enough to be reported in Hawaii. greater than that posed by either vol­ Of these, seven caused severe damage; canoes or earthquakes. five of the seven were generated by earth­ 18. Are advance warnings of approach­ quakes thousands of miles away, such as ing tsunamis possible? the 1946 tsunami that originated in the Yes. Following the very destructive Aleutian Islands and the 1960 tsunami tsunami in 1946, a warning system was that originated near Chile. Each killed developed by the U.S. Coast and Geo­ many people and caused millions of detic Survey (fig. 5). The system is now dollars worth of damage. The tsunamis administered by the National Weather

13 Service of the National Oceanic and sure that new developments are planned Atmospheric Administration (NOAA) for minimum risk to life and property. and is closely tied to the International Obviously, for some areas, it is impos­ Tsunami Information Center. When a sible to avoid some degree of risk. In strong earthquake is centered under or some places the degree of risk may near the Pacific Ocean, a "tsunami watch" indicate that low-density development is issued advising that a tsunami is pos­ requiring few people and only light con­ sible. If large waves are subsequently struction is more appropriate than high- detected at tide stations near the source density development. Individuals and of the earthquake, a "tsunami warning" firms contemplating the purchase of is issued. For any tsunami generated property should have full access to re­ along the margin of the Pacific Ocean, liable facts so they can understand the such a warning gives several hours of nature of the hazards problem. Tax­ notice to Hawaii. This permits safe payers should be aware of the possible evacuation of people and movable prop­ costs of publicly funded relief projects erty from low-lying coastal areas. Warn­ that assist affected property owners. ings now include the advice that most Adequate public knowledge should not tsunamis consist of a series of waves only dispel over-reaction to the hazards that may continue to arrive during a but should also eliminate apathy. The span of several hours; the first wave may problems should be openly acknowl­ not be the strongest. edged and discussed and not hidden or dismissed by wishful thinking. For locally generated tsunamis, such as those of 1868 and 1975, little or no Natural hazards and the problem of response are not unique to Hawaii. advance warning is possible. A fast- Many densely developed areas on main­ acting warning system for the State of land North America are subject to haz­ Hawaii is being developed by the Na­ ards such as floods, earthquakes, and tional Weather Service, but, even when violent storms. Experience has taught im­ operational, the warning will be very portant lessons and has also shown that brief. Any earthquake strong enough to proper planning and construction can cause difficulty in standing or walking markedly reduce the risks. Hawaii, still should be regarded as a tsunami warn­ relatively undeveloped, has the oppor­ ing by people in coastal areas. Long- tunity to make wise choices on patterns term protection from locally generated of land use that will minimize the effects tsunamis will be aided by careful plan­ of natural hazards and protect the liveli­ ning of the location of structures and hood and welfare of residents and visi­ developments, particularly for activities tors. associated with high concentrations of people. 20. What are other sources of informa­ tion about volcanoes, earthquakes, and 19. What do volcanic and other natural tsunamis of Hawaii? hazards mean for people who live, work, The following selected references and visit on Hawaii? describe these natural hazards in more It is important for people to be aware detail than is possible in thisshort booklet. of the hazards and also to realize that Additional information on tsunamis may it is possible to plan and carry out their be obtained by writing to the Inter­ affairs in ways that can minimize the national Tsunami Information Center, effects of the hazards. Often, sensa- P.O. Box 3650, Honolulu, Hawaii 96811. tionalistic publicity has drastically over­ (From material provided by D. W. stated the potential hazards doomsday- Peterson and D. R. Mullineaux) type statements are misleading, irrespon­ sible, and damaging. On the other hand, Photo Credits complacency is equally undesirable and may court disaster. The areas that are Coven Right center, US. Army Corps of relatively susceptible to natural hazards Engineers; bottom, Rev. S. N. McCain, Jr. should be sensibly recognized. Policies Others: Honolulu Advertiser; Hawaii on land use should be adopted that in­ Tribune-Herald, Larry S. Kadooka

14 References Ayre, R. S., 1975, Earthquake and Tsu­ Macdonald, G. A., 1972, Volcanoes: En- nami Hazards in the United States a glewood Cliffs, N. J., Prentice-Hall, Research Assessment: Univ. of Colo­ Inc., 510 p. rado, Inst. of Behavioral Science, Pro­ Mullineaux, D. R., and Peterson, D. W., gram on Technology, Environment and 1974, Volcanic Hazards on the Island Man, Monograph 005, 150 p. of Hawaii: U.S. Geol. Survey Open- Bolt, B.A., and others, 1975, Geological File Rept. 74-239, 61 p. (Out of print, Hazards: New York, Springer-Verlag, but available for consultation in cer­ 328 p. tain U.S. Geol. Survey Offices and in Coffman, J. L, and von Hake, C. A., Hawaiian libraries.) 1973, Earthquake History of the United Richter, C. F., 1958, Elementary Seis­ States: U.S. Dept. of Commerce, Nat'l. mology: San Francisco, W. H. Free­ Oceanic and Atmospheric Admin. man, 768 p. Publication 41-1, 208 p. Stearns, H. T., 1966, Geology of the State Macdonald, C. A., and Abbott, A. T., of Hawaii: Palo Alto, Calif., Pacific 1970, Volcanoes in the Sea: Honolulu, Books, 266 p. Univ. of Hawaii Press, 441 p. Warrick, R. A., 1975, Volcano Hazards Macdonald, G. A., and Hubbard, D. H., in the United States a Research As­ 1973, Volcanoes of the National Parks sessment: Univ. of Colorado, Inst. of in Hawaii (6th edition): Hawaii Nat. Behavioral Science, Program on Tech­ Hist. Assn., 56 p. nology, Environment and Man, Mono­ graph 012,144 p.

d U.S. GOVERNMENT PRINTING OFFICE: 19770-240-966/36 For sale by the Superintendent of Documents, U.S. Qovernment Printing Office Washington, D.C. 20402 - Price 40 cents As the Nation's principal conservation agency, the Department of the Interior has responsibility for most of our nationally owned public lands and natural resources. This includes fostering the wisest use of our land and water resources, protecting our fish and wildlife, preserving the environmental and cultural values of our national parks and historical places, and providing for the enjoyment of life through outdoor recreation. The Department assesses our energy and mineral resources and works to assure that their de­ velopment is in the best interests of all our people. The Department also has a major responsibility for American Indian reservation communities and for people who live in Island Territories under U.S. ad­ ministration.

Cecif D Andrus, Secretary U.S. Department of the Interior

V.E. McKelvey, Director Geological Survey